Arthur J. Gallagher & Co. (AJG) 10-Q 28 Apr 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	3 Months Ended
	Mar. 31, 2017shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Trading Symbol	AJG
Entity Registrant Name	GALLAGHER ARTHUR J & CO
Entity Central Index Key	354,190
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	179,514,000

Consolidated Statement of Earni

Consolidated Statement of Earnings (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Commissions	$ 590.5	$ 566
Fees	370.5	338.2
Supplemental commissions	34.5	32.9
Contingent commissions	53.4	55.2
Investment income	10.8	10.3
Gains on books of business sales	1.4	2.2
Revenues from clean coal activities	351.8	294.8
Other net (losses) revenues	(0.2)	0.8
Total revenues	1,412.7	1,300.4
Compensation	657.6	622.1
Operating	200.4	204.5
Cost of revenues from clean coal activities	366.9	304.4
Interest	29.9	25.8
Depreciation	29.5	24.7
Amortization	64.3	59.3
Change in estimated acquisition earnout payables	11.8	3.9
Total expenses	1,360.4	1,244.7
Earnings before income taxes	52.3	55.7
Benefit for income taxes	(15.5)	(2.2)
Net earnings	67.8	57.9
Net earnings attributable to noncontrolling interests	12.1	11.4
Net earnings attributable to controlling interests	$ 55.7	$ 46.5
Basic net earnings per share:	$ 0.31	$ 0.26
Diluted net earnings per share:	0.31	0.26
Dividends declared per common share	$ 0.39	$ 0.38

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Earnings (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net earnings	$ 67.8	$ 57.9
Change in pension liability, net of taxes	1.2	0.8
Foreign currency translation	58.4	(12.7)
Change in fair value of derivative investments, net of taxes	6.5	(1)
Comprehensive earnings	133.9	45
Comprehensive earnings attributable to noncontrolling interests	13.7	14.2
Comprehensive earnings attributable to controlling interests	$ 120.2	$ 30.8

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Cash and cash equivalents	$ 564	$ 545.5
Restricted cash	1,258	1,392.1
Premiums and fees receivable	2,066.8	1,844.8
Other current assets	594.4	633.7
Total current assets	4,483.2	4,416.1
Fixed assets - net	375.5	377.6
Deferred income taxes	806.7	796.5
Other noncurrent assets	536.2	504.3
Goodwill - net	3,896.9	3,767.8
Amortizable intangible assets - net	1,682.1	1,627.3
Total assets	11,780.6	11,489.6
Premiums payable to insurance and reinsurance companies	3,028.2	2,996.1
Accrued compensation and other accrued liabilities	818.1	772.1
Unearned fees	75.3	69
Other current liabilities	63.7	70.9
Premium financing debt	104.4	125.6
Corporate related borrowings - current	695	578
Total current liabilities	4,784.7	4,611.7
Corporate related borrowings - noncurrent	2,144.7	2,144.6
Other noncurrent liabilities	1,123.9	1,077.5
Total liabilities	8,053.3	7,833.8
Stockholders' equity:
Common stock - issued and outstanding 179.5 shares in 2017 and 178.3 shares in 2016	179.5	178.3
Capital in excess of par value	3,280.3	3,265.5
Retained earnings	901.8	916.4
Accumulated other comprehensive loss	(699.1)	(763.6)
Stockholders' equity attributable to controlling interests	3,662.5	3,596.6
Stockholders' equity attributable to noncontrolling interests	64.8	59.2
Total stockholders' equity	3,727.3	3,655.8
Total liabilities and stockholders' equity	$ 11,780.6	$ 11,489.6

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - shares shares in Millions	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock - issued shares	179.5	178.3
Common stock - outstanding shares	179.5	178.3

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net earnings	$ 67.8	$ 57.9
Adjustments to reconcile net earnings to net cash provided by operating activities:
Net gain on investments and other	(1.4)	(2.2)
Depreciation and amortization	93.8	84
Change in estimated acquisition earnout payables	11.8	3.9
Amortization of deferred compensation and restricted stock	6.2	5.7
Stock-based and other noncash compensation expense	4.1	3.3
Payments on acquisition earnouts in excess of original estimates	(9.1)	(9.4)
Effect of changes in foreign exchange rates	1.5	0.1
Net change in restricted cash	154.2	92.8
Net change in premiums receivable	(206.3)	(60.8)
Net change in premiums payable	(30.1)	(114.2)
Net change in other current assets	56.2	85.9
Net change in accrued compensation and other accrued liabilities	43.1	(19)
Net change in fees receivable/unearned fees		16.6
Net change in income taxes payable	(5.9)	(3.4)
Net change in deferred income taxes	(17.2)	(16.7)
Net change in other noncurrent assets and liabilities	(28)	(17.3)
Unrealized foreign currency remeasurement gain (loss)	29	(7.2)
Net cash provided by operating activities	169.7	100
Cash flows from investing activities:
Net additions to fixed assets	(29.3)	(61.9)
Cash paid for acquisitions, net of cash acquired	(145)	(44.5)
Net proceeds from sales of operations/books of business	1.4	1.7
Net funding of investment transactions	(5.2)	(6.5)
Net cash used by investing activities	(178.1)	(111.2)
Cash flows from financing activities:
Payments on acquisition earnouts	(10.6)	(7.8)
Proceeds from issuance of common stock	20.3	6.8
Tax impact from issuance of common stock		0.6
Repurchases of common stock		(30.4)
Payments to noncontrolling interests	(7.6)	(8.9)
Dividends paid	(71.4)	(68.9)
Net borrowings on premium financing debt facility	(27.8)	(44.3)
Borrowings on line of credit facility	955	332
Repayments on line of credit facility	(838)	(221)
Net cash provided (used) by financing activities	19.9	(41.9)
Effect of changes in foreign exchange rates on cash and cash equivalents	7	(1.9)
Net increase (decrease) in cash and cash equivalents	18.5	(55)
Cash and cash equivalents at beginning of period	545.5	480.4
Cash and cash equivalents at end of period	564	425.4
Supplemental disclosures of cash flow information:
Interest paid	30.1	29
Income taxes paid	$ 12.2	$ 13.8

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity (Unaudited) - 3 months ended Mar. 31, 2017 - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Capital in Excess of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Earnings (Loss) [Member]	Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2016	$ 3,655.8	$ 178.3	$ 3,265.5	$ 916.4	$ (763.6)	$ 59.2
Beginning Balance (in shares) at Dec. 31, 2016		178.3
Net earnings	67.8			55.7		12.1
Dividends paid to noncontrolling interests	(8.1)					(8.1)
Change in pension liability, net of taxes	1.2				1.2
Foreign currency translation	58.4				56.8	1.6
Change in fair value of derivative instruments, net of taxes	6.5				6.5
Compensation expense related to stock option plan grants	4.1		4.1
Common stock issued in:
Two purchase transactions	13.9	$ 0.3	13.6
Two purchase transactions (in shares)		0.3
Stock option plans	$ 17.1	$ 0.6	16.5
Stock option plans (in shares)	0.7	0.6
Employee stock purchase plan	$ 3.2	$ 0.1	3.1
Employee stock purchase plan (in shares)		0.1
Deferred compensation and restricted stock	(22.3)	$ 0.2	(22.5)
Deferred compensation and restricted stock (in shares)		0.2
Cash dividends declared on common stock	(70.3)			(70.3)
Ending Balance at Mar. 31, 2017	$ 3,727.3	$ 179.5	$ 3,280.3	$ 901.8	$ (699.1)	$ 64.8
Ending Balance (in shares) at Mar. 31, 2017		179.5

Consolidated Statement of Stoc8

Consolidated Statement of Stockholders' Equity (Unaudited) (Parenthetical) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Statement of Stockholders' Equity [Abstract]
Tax effect on net change in pension liability	$ 0.8
Net change in fair value of derivative instruments, tax	$ 2.1

Nature of Operations and Basis

Nature of Operations and Basis of Presentation	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Basis of Presentation	1. Nature of Operations and Basis of Presentation Arthur J. Gallagher & Co. and its subsidiaries, collectively referred to herein as we, our, us or the company, provide insurance brokerage and risk management services to a wide variety of commercial, industrial, institutional and governmental organizations through three reportable segments. Commission and fee revenue generated by the brokerage segment is primarily related to the negotiation and placement of insurance for our clients. Fee revenue generated by the risk management segment is primarily related to claims management, information management, risk control consulting (loss control) services and appraisals in the property/casualty market. Investment income and other revenue are generated from our premium financing operations and our investment portfolio, which includes invested cash and restricted funds, as well as clean energy and other investments. We are headquartered in Rolling Meadows, Illinois, have operations in 33 countries and offer client-service capabilities in more than 150 countries globally through a network of correspondent insurance brokers and consultants. We have prepared the accompanying unaudited consolidated financial statements pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures normally included in annual financial statements have been omitted pursuant to such rules and regulations. The unaudited consolidated financial statements included herein are, in the opinion of management, prepared on a basis consistent with our audited consolidated financial statements for the year ended December 31, 2016, except as disclosed in Note 2, and include all normal recurring adjustments necessary for a fair presentation of the information set forth. The quarterly results of operations are not necessarily indicative of the results of operations to be reported for subsequent quarters or the full year. These unaudited consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the notes thereto included in our Annual Report on Form 10-K

Effect of New Accounting Pronou

Effect of New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2017
Accounting Changes and Error Corrections [Abstract]
Effect of New Accounting Pronouncements	2. Effect of New Accounting Pronouncements Business Combinations In January 2017, the Financial Accounting Standards Board (which we refer to as the FASB) issued Accounting Standards Update (which we refer to as ASU) 2017-01, Intangibles – Goodwill and Other In January 2017, the FASB issued ASU 2017-04, non-cash Leases In February 2016, the FASB issued ASU 2016-02, right-of-use We anticipate this guidance will have a material impact on our consolidated financial statements. While we are continuing to assess all potential impacts of the new guidance, we currently believe the most significant impact relates to our real estate operating leases and the related recognition of right-of-use Stock Compensation In March 2016, the FASB issued ASU No. 2016-09, Cash Receipts and Cash Payments In August 2016, the FASB issued ASU No. 2016-15, 2016-15). 2016-15 Consolidations In October 2016, the FASB issued ASU No. 2016-17, 2015-02, Income Taxes In October 2016, the FASB issued ASU No. 2016-16, Restricted Cash In November 2016, the FASB issued Accounting Standards Update 2016-18, Revenue Recognition In May 2014, the FASB issued ASU No. 2014-09, pre-2018 A preliminary assessment to determine the impacts of the new accounting standard has been performed. We are currently implementing new accounting and operational processes which will be impacted by the new guidance, but we are unable to provide information on quantitative impacts at this time. We anticipate this standard will have a material impact on individual lines in our consolidated financial statements, but we do not expect it will have as material an impact on our results of operations on an annual basis. The primary impacts of the new standard to our product and service lines are anticipated to be as follows: Brokerage segment Revenue Expense - Risk management segment We are currently assessing the timing and measurement of revenue recognition under the new guidance for our risk management segment, specifically third party administration contracts among others, and anticipate that more revenue will be initially deferred and recognized over a longer future period of time than under our current accounting policies. Corporate segment We expect that the timing related to recognition of revenue in our corporate segment will remain substantially unchanged.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Business Combinations	3. Business Combinations During the three-month period ended March 31, 2017, we acquired substantially all of the net assets of the following firms in exchange for our common stock and/or cash. These acquisitions have been accounted for using the acquisition method for recording business combinations (in millions except share data): Name and Effective Date of Acquisition Common Common Cash Paid Accrued Escrow Recorded Total Maximum (000s) Construction Risk Solutions, LLC (CRS) January 1, 2017 — $ — $ 27.9 $ — $ 3.1 $ 4.5 $ 35.5 $ 10.0 Hill, Chesson & Woody (HCW) January 1, 2017 — — 34.8 — 0.7 15.6 51.1 24.4 Presidio Group, Inc. (PG) January 1, 2017 — — 41.8 — 4.8 5.5 52.1 15.0 Nine other acquisitions completed in 2017 166 8.4 38.8 — 3.6 7.3 58.1 19.0 166 $ 8.4 $ 143.3 $ — $ 12.2 $ 32.9 $ 196.8 $ 68.4 Common shares issued in connection with acquisitions are valued at closing market prices as of the effective date of the applicable acquisition. We record escrow deposits that are returned to us as a result of adjustments to net assets acquired as reductions of goodwill when the escrows are settled. The maximum potential earnout payables disclosed in the foregoing table represent the maximum amount of additional consideration that could be paid pursuant to the terms of the purchase agreement for the applicable acquisition. The amounts recorded as earnout payables, which are primarily based upon the estimated future operating results of the acquired entities over a two- During the three-month periods ended March 31, 2017 and 2016, we recognized $5.1 million and $4.2 million, respectively, of expense in our consolidated statement of earnings related to the accretion of the discount recorded for earnout obligations in connection with our acquisitions. In addition, during the three-month periods ended March 31, 2017 and 2016, we recognized $6.7 million of expense and $0.3 million of income, respectively, related to net adjustments in the estimated fair value of earnout obligations in connection with revised projections of future performance for 40 and 32 acquisitions, respectively. The aggregate amount of maximum earnout obligations related to acquisitions was $565.3 million as of March 31, 2017, of which $268.3 million was recorded in our consolidated balance sheet as of March 31, 2017, based on the estimated fair value of the expected future payments to be made. The following is a summary of the estimated fair values of the net assets acquired at the date of each acquisition made in the three-month period ended March 31, 2017 (in millions): CRS HCW PG Nine Other Acquisitions Total Cash $ — $ — $ — $ 2.2 $ 2.2 Other current assets 3.6 2.1 2.4 3.0 11.1 Fixed assets — — 0.5 0.6 1.1 Noncurrent assets — 0.2 — — 0.2 Goodwill 12.3 26.2 25.0 28.4 91.9 Expiration lists 22.7 22.3 26.8 33.3 105.1 Non-compete 0.1 0.4 0.3 0.2 1.0 Total assets acquired 38.7 51.2 55.0 67.7 212.6 Current liabilities 3.2 0.1 2.9 4.1 10.3 Noncurrent liabilities — — — 5.5 5.5 Total liabilities assumed 3.2 0.1 2.9 9.6 15.8 Total net assets acquired $ 35.5 $ 51.1 $ 52.1 $ 58.1 $ 196.8 Among other things, these acquisitions allow us to expand into desirable geographic locations, further extend our presence in the retail and wholesale insurance brokerage services and risk management industries and increase the volume of general services currently provided. The excess of the purchase price over the estimated fair value of the tangible net assets acquired at the acquisition date was allocated to goodwill, expiration lists and non-compete Provisional estimates of fair value are established at the time of each acquisition and are subsequently reviewed within the first year of operations subsequent to the acquisition date to determine the necessity for adjustments. The fair value of the tangible assets and liabilities for each applicable acquisition at the acquisition date approximated their carrying values. The fair value of expiration lists was established using the excess earnings method, which is an income approach based on estimated financial projections developed by management for each acquired entity using market participant assumptions. Revenue growth and attrition rates generally ranged from 3.0% to 3.3% and 5.5% to 7.3%, respectively, for our 2016 acquisitions for which valuations were performed in 2017. We estimate the fair value as the present value of the benefits anticipated from ownership of the subject customer list in excess of returns required on the investment in contributory assets necessary to realize those benefits. The rate used to discount the net benefits was based on a risk-adjusted rate that takes into consideration market-based rates of return and reflects the risk of the asset relative to the acquired business. These discount rates generally ranged from 12.0% to 12.2% for our 2016 acquisitions for which valuations were performed in 2017. The fair value of non-compete non-compete non-compete non-compete Of the $105.1 million of expiration lists and $1.0 million of non-compete Our consolidated financial statements for the three-month period ended March 31, 2017 include the operations of the acquired entities from their respective acquisition dates. The following is a summary of the unaudited pro forma historical results, as if these entities had been acquired at January 1, 2016 (in millions, except per share data): Three-month period ended March 31, 2017 2016 Total revenues $ 1,414.4 $ 1,317.2 Net earnings attributable to controlling interests 55.7 47.3 Basic net earnings per share 0.31 0.27 Diluted net earnings per share 0.31 0.27 The unaudited pro forma results above have been prepared for comparative purposes only and do not purport to be indicative of the results of operations which actually would have resulted had these acquisitions occurred at January 1, 2016, nor are they necessarily indicative of future operating results. Annualized revenues of entities acquired during the three-month period ended March 31, 2017 totaled approximately $62.5 million. For the three-month

Other Current Assets

Other Current Assets	3 Months Ended
	Mar. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Current Assets	4. Other Current Assets Major classes of other current assets consist of the following (in millions): March 31, 2017 December 31, 2016 Premium finance advances and loans $ 220.1 $ 241.2 Accrued supplemental, direct bill and other receivables 170.9 177.2 Refined coal production related receivables 121.5 136.9 Prepaid expenses 81.9 78.4 Total other current assets $ 594.4 $ 633.7 The premium finance loans represent short-term loans which we make to many of our brokerage related clients and other non-brokerage

Intangible Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	5. Intangible Assets The carrying amount of goodwill at March 31, 2017 and December 31, 2016 allocated by domestic and foreign operations is as follows (in millions): At March 31, 2017 Brokerage Risk Management Corporate Total United States $ 2,201.6 $ 23.5 $ — $ 2,225.1 United Kingdom 667.8 4.3 — 672.1 Canada 293.8 — — 293.8 Australia 410.9 — — 410.9 New Zealand 208.5 0.3 — 208.8 Other foreign 83.3 — 2.9 86.2 Total goodwill - net $ 3,865.9 $ 28.1 $ 2.9 $ 3,896.9 At December 31, 2016 United States $ 2,115.0 $ 23.5 $ — $ 2,138.5 United Kingdom 662.2 4.3 — 666.5 Canada 292.2 — — 292.2 Australia 382.7 — — 382.7 New Zealand 205.0 0.3 — 205.3 Other foreign 79.8 — 2.8 82.6 Total goodwill - net $ 3,736.9 $ 28.1 $ 2.8 $ 3,767.8 The changes in the carrying amount of goodwill for the three-month period ended March 31, 2017 are as follows (in millions): Brokerage Risk Management Corporate Total Balance as of December 31, 2016 $ 3,736.9 $ 28.1 $ 2.8 $ 3,767.8 Goodwill acquired during the period 91.9 — — 91.9 Goodwill adjustments due to appraisals and other acquisition adjustments 1.6 — — 1.6 Foreign currency translation adjustments during the period 35.5 — 0.1 35.6 Balance as of March 31, 2017 $ 3,865.9 $ 28.1 $ 2.9 $ 3,896.9 Major classes of amortizable intangible assets at March 31, 2017 and December 31, 2016 consist of the following (in millions): March 31, 2017 December 31, 2016 Expiration lists $ 2,880.5 $ 2,757.6 Accumulated amortization - expiration lists (1,210.1 ) (1,143.0 ) 1,670.4 1,614.6 Non-compete 50.5 49.3 Accumulated amortization - non-compete (43.3 ) (42.1 ) 7.2 7.2 Trade names 24.4 24.0 Accumulated amortization - trade names (19.9 ) (18.5 ) 4.5 5.5 Net amortizable assets $ 1,682.1 $ 1,627.3 Estimated aggregate amortization expense for each of the next five years is as follows: 2017 (remaining nine months) $ 190.8 2018 239.9 2019 225.8 2020 209.6 2021 187.2 Total $ 1,053.3

Credit and Other Debt Agreement

Credit and Other Debt Agreements	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Credit and Other Debt Agreements	6. Credit and Other Debt Agreements The following is a summary of our corporate and other debt (in millions): March 31, 2017 December 31, 2016 Note Purchase Agreements: Semi-annual payments of interest, fixed rate of 6.44%, balloon due August 3, 2017 $ 300.0 $ 300.0 Semi-annual payments of interest, fixed rate of 5.85%, $50 million due November 30, 2018 and November 30, 2019 100.0 100.0 Semi-annual payments of interest, fixed rate of 2.80%, balloon due June 24, 2018 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.20%, balloon due June 24, 2019 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.99%, balloon due July 10, 2020 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.48%, balloon due June 24, 2020 50.0 50.0 Semi-annual payments of interest, fixed rate of 5.18%, balloon due February 10, 2021 75.0 75.0 Semi-annual payments of interest, fixed rate of 3.69%, balloon due June 14, 2022 200.0 200.0 Semi-annual payments of interest, fixed rate of 5.49%, balloon due February 10, 2023 50.0 50.0 Semi-annual payments of interest, fixed rate of 4.13%, balloon due June 24, 2023 200.0 200.0 Semi-annual payments of interest, fixed rate of 4.58%, balloon due February 27, 2024 325.0 325.0 Semi-annual payments of interest, fixed rate of 4.31%, balloon due June 24, 2025 200.0 200.0 Semi-annual payments of interest, fixed rate of 4.73%, balloon due February 27, 2026 175.0 175.0 Semi-annual payments of interest, fixed rate of 4.36%, balloon due June 24, 2026 150.0 150.0 Semi-annual payments of interest, fixed rate of 4.40%, balloon due June 2, 2026 175.0 175.0 Semi-annual payments of interest, fixed rate of 3.46%, balloon due December 1, 2027 100.0 100.0 Semi-annual payments of interest, fixed rate of 4.55%, balloon due June 2, 2028 75.0 75.0 Semi-annual payments of interest, fixed rate of 4.98%, balloon due February 27, 2029 100.0 100.0 Semi-annual payments of interest, fixed rate of 4.70%, balloon due June 2, 2031 25.0 25.0 Total Note Purchase Agreements 2,450.0 2,450.0 Credit Agreement: Periodic payments of interest and principal, prime or LIBOR plus up to 1.45%, expires April 8, 2021 395.0 278.0 Premium Financing Debt Facility - expires May 18, 2017: Periodic payments of interest and principal, Interbank rates plus 1.05% for Facility B; plus 0.55% for Facilities C and D Facility B AUD denominated tranche 66.4 100.7 NZD denominated tranche 8.4 9.0 Facility C and D AUD denominated tranche 19.2 5.6 NZD denominated tranche 10.4 10.3 Total Premium Financing Debt Facility 104.4 125.6 Total corporate and other debt 2,949.4 2,853.6 Less unamortized debt acquisition costs on Note Purchase Agreements (5.3 ) (5.4 ) Net corporate and other debt $ 2,944.1 $ 2,848.2

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	7. Earnings Per Share The following table sets forth the computation of basic and diluted net earnings per share (in millions, except per share data): Three-month period ended March 31, 2017 2016 Net earnings attributable to controlling interests $ 55.7 $ 46.5 Weighted average number of common shares outstanding 178.9 177.0 Dilutive effect of stock options using the treasury stock method 1.7 0.6 Weighted average number of common and common equivalent shares outstanding 180.6 177.6 Basic net earnings per share $ 0.31 $ 0.26 Diluted net earnings per share $ 0.31 $ 0.26 Options to purchase 0.3 million and 4.3 million shares of common stock were outstanding at March 31, 2017 and 2016, respectively, but were not included in the computation of the dilutive effect of stock options for the three-month

Stock Option Plans

Stock Option Plans	3 Months Ended
	Mar. 31, 2017
Text Block [Abstract]
Stock Option Plans	8. Stock Option Plans On May 13, 2014, our stockholders approved the Arthur J. Gallagher 2014 Long-Term Incentive Plan (which we refer to as the LTIP), which replaced our previous stockholder-approved Arthur J. Gallagher & Co. 2011 Long-Term Incentive Plan (which we refer to as the 2011 LTIP). The LTIP term began May 13, 2014 and terminates on the date of the annual meeting of stockholders in 2021, unless terminated earlier by our board of directors. All of our officers, employees and non-employee non-qualified Shares of our common stock available for issuance under the LTIP include authorized and unissued shares of common stock or authorized and issued shares of common stock reacquired and held as treasury shares or otherwise, or a combination thereof. The number of available shares will be reduced by the aggregate number of shares that become subject to outstanding awards granted under the LTIP. To the extent that shares subject to an outstanding award granted under either the LTIP or the 2011 LTIP are not issued or delivered by reason of the expiration, termination, cancellation or forfeiture of such award or by reason of the settlement of such award in cash, then such shares will again be available for grant under the LTIP. Shares withheld to satisfy tax withholding requirements upon the vesting of awards other than stock options and stock appreciation rights will also be available for grant under the LTIP. Shares that are subject to a stock appreciation right and were not issued upon the net settlement or net exercise of such stock appreciation right, shares that are used to pay the exercise price of an option, delivered to or withheld by us to pay withholding taxes related to stock options or stock appreciation rights, and shares that are purchased on the open market with the proceeds of an option exercise, may not again be made available for issuance. The maximum number of shares available under the LTIP for restricted stock, restricted stock unit awards and performance unit awards settled with stock (i.e., all awards other than stock options and stock appreciation rights) is 0.4 million at March 31, 2017. To the extent necessary to be qualified performance-based compensation under Section 162(m) of the Internal Revenue Code (which we refer to as the IRC): (i) the maximum number of shares with respect to which options or stock appreciation rights or a combination thereof that may be granted during any fiscal year to any person is 200,000; (ii) the maximum number of shares with respect to which performance-based restricted stock or restricted stock units that may be granted during any fiscal year to any person is 100,000; (iii) the maximum amount that may be payable with respect to cash-settled performance units granted during any fiscal year to any person is $5.0 million; and (iv) the maximum number of shares with respect to which stock-settled performance units may be granted during any fiscal year to any person is 100,000. The LTIP provides for the grant of stock options, which may be either tax-qualified non-qualified non-qualified tax-qualified non-qualified tax-qualified Upon exercise, the option exercise price may be paid in cash, by the delivery of previously owned shares of our common stock, through a net-exercise non-transferable. On March 16, 2017, the compensation committee granted 1,650,400 options under the 2014 LTIP to our officers and key employees that become exercisable at the rate of 34%, 33% and 33% on the anniversary date of the grant in 2020, 2021 and 2022, respectively. On March 17, 2016, the compensation committee granted 2,576,700 options under the 2014 LTIP to our officers and key employees that become exercisable at the rate of 34%, 33% and 33% on the anniversary date of the grant in 2019, 2020 and 2021, respectively. The 2017 and 2016 options expire seven years from the date of grant, or earlier in the event of certain terminations of employment. For certain of our executive officers age 55 or older, stock options awarded in 2017 and 2016 are no longer subject to forfeiture upon such officers’ departure from the company after two years from the date of grant. Our stock option plans provide for the immediate vesting of all outstanding stock option grants in the event of a change in control of our company, as defined in the applicable plan documents. During the three-month periods ended March 31, 2017 and 2016, we recognized $4.1 million and $3.3 million, respectively, of compensation expense related to our stock option grants. For purposes of expense recognition, the estimated fair values of the stock option grants are amortized to expense over the options’ vesting period. We estimated the fair value of stock options at the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions: 2017 2016 Expected dividend yield 2.8 % 3.0 % Expected risk-free interest rate 2.3 % 1.6 % Volatility 27.2 % 27.7 % Expected life (in years) 5.0 5.5 Option valuation models require the input of highly subjective assumptions including the expected stock price volatility. The Black-Scholes option pricing model was developed for use in estimating the fair value of traded options which have no vesting restrictions and are fully transferable. Because our employee and director stock options have characteristics significantly different from those of traded options, and because changes in the selective input assumptions can materially affect the fair value estimate, in management’s opinion, the existing models do not necessarily provide a reliable single measure of the fair value of our employee and non-employee The following is a summary of our stock option activity and related information for 2017 (in millions, except exercise price and year data): Three-month period ended March 31, 2017 Shares Under Option Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Beginning balance 10.3 $ 41.40 Granted 1.6 56.86 Exercised (0.7 ) 30.98 Forfeited or canceled — — Ending balance 11.2 $ 44.35 4.53 $ 137.4 Exercisable at end of period 3.2 $ 37.28 2.38 $ 61.5 Ending vested and expected to vest 11.0 $ 44.26 4.50 $ 135.6 Options with respect to 2.3 million shares (less any shares of restricted stock issued under the LTIP - see Note 10 to these unaudited consolidated financial statements) were available for grant under the LTIP at March 31, 2017. The total intrinsic value of options exercised during the three-month periods ended March 31, 2017 and 2016 was $16.6 million and $1.7 million, respectively. As of March 31, 2017, we had approximately $56.3 million of total unrecognized compensation expense related to nonvested options. We expect to recognize that cost over a weighted average period of approximately four years. Other information regarding stock options outstanding and exercisable at March 31, 2017 is summarized as follows (in millions, except exercise price and year data): Options Outstanding Options Exercisable Range of Exercise Prices Number Weighted (in years) Weighted Number Weighted $ 23.76 - $ 39.17 3.2 2.17 $ 35.68 2.6 $ 35.01 43.71 - 46.17 4.5 5.53 44.77 — — 46.87 - 49.55 1.9 3.97 46.89 0.6 46.87 56.86 - 56.86 1.6 6.96 56.86 — — $ 23.76 - $ 56.86 11.2 4.53 $ 44.35 3.2 $ 37.28

Deferred Compensation

Deferred Compensation	3 Months Ended
	Mar. 31, 2017
Compensation Related Costs [Abstract]
Deferred Compensation	9. Deferred Compensation We have a Deferred Equity Participation Plan (which we refer to as the DEPP), which is a non-qualified one-year one-year sub-plans sub-plans) Our common stock that is issued to or purchased by the rabbi trust as a contribution under the DEPP is valued at historical cost, which equals its fair market value at the date of grant or date of purchase. When common stock is issued, we record an unearned deferred compensation obligation as a reduction of capital in excess of par value in the accompanying consolidated balance sheet, which is amortized to compensation expense ratably over the vesting period of the participants. Future changes in the fair market value of our common stock owed to the participants do not have any impact on the amounts recorded in our consolidated financial statements. In the first quarter of each of 2017 and 2016, the compensation committee approved $14.0 million and $10.1 million, respectively, of awards in the aggregate to certain key executives under the DEPP that were contributed to the rabbi trust in first quarter 2017 and 2016, respectively. We contributed cash to the rabbi trust and instructed the trustee to acquire a specified number of shares of our common stock on the open market to fund these 2017 and 2016 awards. During the three-month periods ended March 31, 2017 and 2016, we charged $1.8 million and $1.4 million, respectively, to compensation expense related to these awards. In the second quarter of 2016, the compensation committee approved $13.6 million of awards under the sub-plans sub-plans At March 31, 2017 and December 31, 2016, we recorded $66.4 million (related to 2.7 million shares) and $46.8 million (related to 2.4 million shares), respectively, of unearned deferred compensation as a reduction of capital in excess of par value in the accompanying consolidated balance sheet. The total intrinsic value of our unvested equity based awards under the plan at March 31, 2017 and December 31, 2016 was $153.7 million and $125.5 million, respectively. During the three-month period ended March 31, 2017, there were no distributions under the DEPP. During the three-month period ended March 31, 2016, cash and equity awards with an aggregate fair value of $4.9 million were vested and distributed to executives under the Age 62 Plan We have a Deferred Cash Participation Plan (which we refer to as the DCPP), which is a non-qualified three-month

Restricted Stock, Performance S

Restricted Stock, Performance Share and Cash Awards	3 Months Ended
	Mar. 31, 2017
Text Block [Abstract]
Restricted Stock, Performance Share and Cash Awards	10. Restricted Stock, Performance Share and Cash Awards Restricted Stock Awards As discussed in Note 8 to these unaudited consolidated financial statements, on May 13, 2014, our stockholders approved the LTIP, which replaced our previous stockholder-approved 2011 LTIP. The LTIP provides for the grant of a stock award either as restricted stock or as restricted stock units. In either case, the compensation committee may determine that the award will be subject to the attainment of performance measures over an established performance period. Stock awards and the related dividend equivalents are non-transferable The agreements awarding restricted stock units under the LTIP will specify whether such awards may be settled in shares of our common stock, cash or a combination of shares and cash and whether the holder will be entitled to receive dividend equivalents, on a current or deferred basis, with respect to such award. Prior to the settlement of a restricted stock unit, the holder of a restricted stock unit will have no rights as a stockholder of the company. The maximum number of shares available under the LTIP for restricted stock, restricted stock units and performance unit awards settled with stock (i.e., all awards other than stock options and stock appreciation rights) is 2.0 million. At March 31, 2017, 0.4 million shares were available for grant under the LTIP for such awards. In the first quarter of each of 2017 and 2016, we granted 477,500 and 466,600 restricted stock units, respectively, to employees under the LTIP, with an aggregate fair value of $26.8 million and $20.4 million, respectively, at the date of grant. These 2017 and 2016 awards of restricted stock units vest as follows: 477,500 units granted in first quarter 2017 and 466,600 units granted in first quarter 2016, vest in full based on continued employment through March 16, 2021 and March 11, 2020, respectively. For certain of our executive officers age 55 or older, restricted stock units awarded in 2017 and 2016 are not subject to forfeiture upon such officers’ departure from the company after two years from the date of grant. We account for restricted stock awards at historical cost, which equals its fair market value at the date of grant, which is amortized to compensation expense ratably over the vesting period of the participants. Future changes in the fair value of our common stock that is owed to the participants do not have any impact on the amounts recorded in our consolidated financial statements. During the three-month periods ended March 31, 2017 and 2016, we recognized $4.0 million and $4.0 million, respectively, to compensation expense related to restricted stock unit awards granted in 2007 through 2017. The total intrinsic value of unvested restricted stock units at March 31, 2017 and 2016 was $90.4 million and $62.9 million, respectively. During the three-month period ended March 31, 2017, equity awards (including accrued dividends) with an aggregate fair value of $21.6 million was vested and distributed to employees under this plan. During the three-month period ended March 31, 2016, equity awards (including accrued dividends) with an aggregate fair value of $14.2 million was vested and distributed to employees under this plan. Performance Share Awards On March 16, 2017 and March 17, 2016, pursuant to the LTIP, the compensation committee approved 86,250 and 72,900, respectively of provisional performance unit awards, with an aggregate fair value of $4.9 million and $3.2 million, respectively, for future grants to our officers. Each performance unit award was equivalent to the value of one share of our common stock on the date such provisional award was approved. In 2016, these awards were subject to a one-year two-year one-for-one Cash Awards On March 16, 2017, pursuant to our Performance Unit Program (which we refer to as the Program), the compensation committee approved provisional cash awards of $14.3 million in the aggregate for future grants to our officers and key employees that are denominated in units (255,000 units in the aggregate), each of which was equivalent to the value of one share of our common stock on the date the provisional award was approved. The Program consists of a one-year two-year On March 17, 2016, pursuant to the Program, the compensation committee approved provisional cash awards of $17.4 million in the aggregate for future grant to our officers and key employees that are denominated in units (397,000 units in the aggregate), each of which was equivalent to the value of one share of our common stock on the date the provisional awards were approved. Terms of the 2016 provisional awards were similar to the terms of the 2017 provisional awards. Based on our performance for 2016, we granted 383,000 units under the Program in first quarter 2017 that will fully vest on January 1, 2019. During the three-month period ended March 31, 2017, we recognized $2.6 million to compensation expense related to these awards. We did not recognize any compensation expense during 2016 related to the 2016 awards. On March 11, 2015, pursuant to the Program, the compensation committee approved provisional cash awards of $14.6 million in the aggregate for future grant to our officers and key employees that are denominated in units (315,000 units in the aggregate), each of which was equivalent to the value of one share of our common stock on the date the provisional awards were approved. Terms of the 2015 provisional awards were similar to the terms of the 2016 provisional awards. Based on our performance for 2015, we granted 294,000 units under the Program in first quarter 2016 that will fully vest on January 1, 2018. During the three-month period ended March 31, 2017 and 2016, we recognized $3.1 million and $1.6 million, respectively, to compensation expense related to these awards. On March 12, 2014, pursuant to the Program, the compensation committee approved provisional cash awards of $10.8 million in the aggregate for future grant to our officers and key employees that are denominated in units (229,000 units in the aggregate), each of which was equivalent to the value of one share of our common stock on the date the provisional awards were approved. Terms of the 2014 provisional awards were similar to the terms of the 2015 provisional awards. Based on our performance for 2014, we granted 220,000 units under the Program in first quarter 2015 that will fully vest on January 1, 2017. During the three-month period ended March 31, 2016, we recognized $0.9 million, to compensation expense related to these awards. During the three-month period ended March 31, 2017, cash awards related to the 2014 provisional award with an aggregate fair value of $9.3 million (0.2 million units in the aggregate) were vested and distributed to employees under the Program. During the three-month period ended March 31, 2016, cash awards related to the 2013 provisional award with an aggregate fair value of $11.2 million (0.2 million units in the aggregate) were vested and distributed to employees under the Program.

Investments

Investments	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investments	11. Investments The following is a summary of our investments, included in other noncurrent assets in the consolidated balance sheet, and the related funding commitments (in millions): March 31, 2017 December 31, Funding 2016 Assets Commitments Assets Chem-Mod LLC $ 4.0 $ — $ 4.0 Chem-Mod International LLC 2.0 — 2.0 Clean-coal investments: Controlling interest in six limited liability companies that own fourteen 2009 Era Clean Coal Plants 13.3 — 14.3 Non-controlling 0.7 — 0.7 Controlling interest in seventeen limited liability companies that own nineteen 2011 Era Clean Coal Plants 69.5 — 69.0 Other investments 3.8 0.4 3.7 Total investments $ 93.3 $ 0.4 $ 93.7

Derivatives and Hedging Activit

Derivatives and Hedging Activity	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activity	12. Derivatives and Hedging Activity We are exposed to market risks, including changes in foreign currency exchange rates and interest rates. To manage the risk related to these exposures, we enter into various derivative instruments that reduce these risks by creating offsetting exposures. We generally do not enter into derivative transactions for trading or speculative purposes. Foreign Exchange Risk Management We are exposed to foreign exchange risk when we earn revenues, pay expenses, or enter into monetary intercompany transfers denominated in a currency that differs from our functional currency, or other transactions that are denominated in a currency other than our functional currency. We use foreign exchange derivatives, typically forward contracts and options, to reduce our overall exposure to the effects of currency fluctuations on cash flows. These exposures are hedged, on average, for less than two years. Interest Rate Risk Management We enter into various long term debt agreements. We use interest rate derivatives, typically swaps, to reduce our exposure to the effects of interest rate fluctuations on the forecasted interest rates for up to two years into the future. We have not received or pledged any collateral related to derivative arrangements at March 31, 2017. The notional and fair values of derivative instruments are as follows at March 31, 2017 and December 31, 2016 (in millions): Notional Amount Derivatives Assets (1) Derivative Liabilities (2) March 31, 2017 Dec 31, 2016 March 31, 2017 Dec 31, 2016 March 31, 2017 Dec 31, 2016 Derivatives accounted for as hedges: Interest rate contracts $ 250.0 $ 200.0 $ 12.2 $ 11.4 $ — $ — Foreign exchange contracts (3) 6.2 4.1 5.2 2.1 12.8 17.5 Total $ 256.2 $ 204.1 $ 17.4 $ 13.5 $ 12.8 $ 17.5 (1) Included within other current assets, $15.0 million and $12.5 million at March 31, 2017 and December 31, 2016, respectively, and other non-current (2) Included within other current liabilities, $8.9 million and $11.8 million at March 31, 2017 and December 31, 2016, respectively, and other non-current (3) Included within foreign exchange contracts at March 31, 2017 were $95.5 million of call options offset with $95.5 million of put options, and $46.9 million of buy forwards offset with $53.1 million of sell forwards. Included within foreign exchange contracts at December 31, 2016 were $78.3 million of call options offset with $78.3 million of put options, and $61.6 million of buy forwards offset with $57.5 million of sell forwards. The amounts of derivative gains (losses) recognized in accumulated other comprehensive loss were as follows (in millions): Commission Compensation Operating Interest Total March 31, 2017 Cash flow hedges: Interest rate contracts $ — $ — $ — $ 0.8 $ 0.8 Foreign exchange contracts 2.4 1.8 1.2 — 5.4 Total $ 2.4 $ 1.8 $ 1.2 $ 0.8 $ 6.2 March 31, 2016 Cash flow hedges: Interest rate contracts $ — $ — $ — $ 1.1 $ 1.1 Foreign exchange contracts (3.4 ) — — — (3.4 ) Total $ (3.4 ) $ — $ — $ 1.1 $ (2.3 ) The amounts of derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion) were as follows (in millions): Commission Revenue Compensation Expense Operating Expense Interest Expense Total March 31, 2017 Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts (2.8 ) 0.2 0.2 — (2.4 ) Total $ (2.8 ) $ 0.2 $ 0.2 $ — $ (2.4 ) March 31, 2016 Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts (1.2 ) — — — (1.2 ) Total $ (1.2 ) $ — $ — $ — $ (1.2 ) We estimate that approximately $4.7 million of pretax gains currently included within accumulated other comprehensive loss will be reclassified into earnings in the next twelve months. The amount of gain (loss) recognized in earnings on the ineffective portion of derivatives for three-months ended March 31, 2017 and 2016 was $0.2 million and $0.3 million, respectively.

Commitments, Contingencies and

Commitments, Contingencies and Off-Balance Sheet Arrangements	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies and Off-Balance Sheet Arrangements	13. Commitments, Contingencies and Off-Balance In connection with our investing and operating activities, we have entered into certain contractual obligations and commitments. Our future minimum cash payments, including interest, associated with our contractual obligations pursuant to the note purchase agreements, Credit Agreement, Premium Financing Debt Facility, operating leases and purchase commitments at March 31, 2017 were as follows (in millions): Payments Due by Period Contractual Obligations 2017 2018 2019 2020 2021 Thereafter Total Note purchase agreements $ 300.0 $ 100.0 $ 100.0 $ 100.0 $ 75.0 $ 1,775.0 $ 2,450.0 Credit Agreement 395.0 — — — — — 395.0 Premium Financing Debt Facility 104.4 — — — — — 104.4 Interest on debt 85.4 92.9 88.9 84.3 79.4 280.5 711.4 Total debt obligations 884.8 192.9 188.9 184.3 154.4 2,055.5 3,660.8 Operating lease obligations 79.0 88.7 73.3 60.7 50.3 121.5 473.5 Less sublease arrangements (0.8 ) (0.4 ) (0.1 ) (0.1 ) — — (1.4 ) Outstanding purchase obligations 42.3 32.3 17.3 7.3 2.2 — 101.4 Total contractual obligations $ 1,005.3 $ 313.5 $ 279.4 $ 252.2 $ 206.9 $ 2,177.0 $ 4,234.3 The amounts presented in the table above may not necessarily reflect our actual future cash funding requirements, because the actual timing of future payments may vary from the stated contractual obligation. Outstanding purchase commitments in the table above include $7.2 million related to expenditures on our new corporate headquarters. Note Purchase Agreements, Credit Agreement and Premium Financing Debt Facility Operating Lease Obligations tax-increment We generally operate in leased premises at our other locations. Certain of these leases have options permitting renewals for additional periods. In addition to minimum fixed rentals, a number of leases contain annual escalation clauses which are generally related to increases in an inflation index. We have leased certain office space to several non-affiliated Outstanding Purchase Obligations Off-Balance Sheet Commitments Amount of Commitment Expiration by Period Total Amounts Committed Off-Balance 2017 2018 2019 2020 2021 Thereafter Letters of credit $ — $ — $ — $ — $ — $ 21.1 $ 21.1 Financial guarantees 0.1 0.2 0.2 0.2 0.2 1.4 2.3 Funding commitments — — — — — 0.4 0.4 Total commitments $ 0.1 $ 0.2 $ 0.2 $ 0.2 $ 0.2 $ 22.9 $ 23.8 Since commitments may expire unused, the amounts presented in the table above do not necessarily reflect our actual future cash funding requirements. See the Off-Balance Since January 1, 2002, we have acquired 432 companies, all of which were accounted for using the acquisition method for recording business combinations. Substantially all of the purchase agreements related to these acquisitions contain provisions for potential earnout obligations. For all of our acquisitions made in the period from 2014 to 2017 that contain potential earnout obligations, such obligations are measured at fair value as of the acquisition date and are included on that basis in the recorded purchase price consideration for the respective acquisition. The amounts recorded as earnout payables are primarily based upon estimated future operating results of the acquired entities over a two- Off-Balance Sheet Debt - At March 31, 2017, we had posted two letters of credit totaling $9.3 million, in the aggregate, related to our self-insurance rent-a-captive Litigation, Regulatory and Taxation Matters - non-compete In July 2014, we were named in a lawsuit that asserts that we and other defendants are liable for infringement of a patent held by Nalco Company. The complaint sought a judgment of infringement, damages, costs and attorneys’ fees, and injunctive relief. Along with other defendants, we disputed the allegation of infringement and have defended this matter vigorously. We filed a motion to dismiss the complaint on behalf of all defendants, alleging no infringement of Nalco’s intellectual property. This motion, and similar motions attacking amended complaints filed by Nalco, were granted. On April 20, 2016, the court dismissed Nalco’s complaints and disallowed any further opportunity to amended or refile. Although Nalco has appealed this ruling, we believe that the probability of a material loss is remote. However, litigation is inherently uncertain and it is not possible for us to predict the ultimate disposition of this proceeding. Our micro-captive advisory services are under investigation by the Internal Revenue Service (IRS). Additionally, the IRS has initiated audits for the 2012 tax year of over 100 of the micro-captive insurance companies organized and/or managed by us. Among other matters, the IRS is investigating whether we have been acting as a tax shelter promoter in connection with these operations. While the IRS has not made specific allegations relating to our operations, if the IRS were to successfully assert that the micro-captives organized and/or managed by us do not meet the requirements of IRC Section 831(b), we could be held liable to pay monetary claims by the IRS and/or our micro-captive clients, and our future earnings from our micro-captive operations could be materially adversely affected, any of which events, could negatively impact the overall captive business and adversely affect our consolidated results of operations and financial condition. Due to the fact that the IRS has not made any allegation against us or completed its audits of our clients, we are not able to reasonably estimate the amount of any potential loss in connection with this investigation. Contingent Liabilities - Tax-advantaged Investments No Longer Held -

Accumulated Other Comprehensive

Accumulated Other Comprehensive Earnings (Loss)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Earnings (Loss)	14. Accumulated Other Comprehensive Earnings (Loss) The after-tax Pension Liability Foreign Currency Translation Fair Value of Derivative Investments Accumulated Comprehensive Earnings (Loss) Balance as of December 31, 2016 $ (47.3 ) $ (709.2 ) $ (7.1 ) $ (763.6 ) Net change in period 1.2 56.8 6.5 64.5 Balance as of March 31, 2017 $ (46.1 ) $ (652.4 ) $ (0.6 ) $ (699.1 ) The foreign currency translation during the three-month period ended March 31, 2017 primarily relates to the net impact of changes in the value of the local currencies relative to the U.S. dollar for our operations in Australia, Canada, the Caribbean, India, New Zealand and the U.K. During the three-month periods ended March 31, 2017 and 2016, $1.4 million and $1.5 million, respectively, of expense related to the pension liability was reclassified from accumulated other comprehensive earnings (loss) to compensation expense in the statement of earnings. During the three-month periods ended March 31, 2017 and 2016, $2.4 million and $1.2 million of expense, respectively, related to the fair value of derivative investments, was reclassified from accumulated other comprehensive earnings (loss) to the statement of earnings. During the three-month

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Segment Information	15. Segment Information We have three reportable segments: brokerage, risk management and corporate. The brokerage segment is primarily comprised of our retail and wholesale insurance brokerage operations. The brokerage segment generates revenues through commissions paid by insurance underwriters and through fees charged to our clients. Our brokers, agents and administrators act as intermediaries between insurers and their customers and we do not assume underwriting risks. The risk management segment provides contract claim settlement and administration services for enterprises that choose to self-insure some or all of their property/casualty coverages and for insurance companies that choose to outsource some or all of their property/casualty claims departments. These operations also provide claims management, loss control consulting and insurance property appraisal services. Revenues are principally generated on a negotiated per-claim per-service The corporate segment manages our clean energy and other investments. In addition, the corporate segment reports the financial information related to our debt, and certain corporate and acquisition-related activities. Allocations of investment income and certain expenses are based on reasonable assumptions and estimates primarily using revenue, headcount and other information. We allocate the provision for income taxes to the brokerage and risk management segments using the local country statutory rates. Reported operating results by segment would change if different methods were applied. Financial information relating to our segments for the three-month periods ended March 31, 2017 and 2016 is as follows (in millions): Three -month ended March 31, 2017 2016 Brokerage Total revenues $ 878.5 $ 825.5 Earnings before income taxes $ 117.7 $ 100.0 Identifiable assets at March 31, 2017 and 2016 $ 9,422.9 $ 8,681.9 Risk Management Total revenues $ 182.6 $ 179.3 Earnings before income taxes $ 22.9 $ 24.0 Identifiable assets at March 31, 2017 and 2016 $ 691.1 $ 690.4 Corporate Total revenues $ 351.6 $ 295.6 Loss before income taxes $ (88.3 ) $ (68.3 ) Identifiable assets at March 31, 2017 and 2016 $ 1,666.9 $ 1,340.3

Effect of New Accounting Pron24

Effect of New Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2017
Accounting Changes and Error Corrections [Abstract]
Business Combinations	Business Combinations In January 2017, the Financial Accounting Standards Board (which we refer to as the FASB) issued Accounting Standards Update (which we refer to as ASU) 2017-01,
Intangibles - Goodwill and Other	Intangibles – Goodwill and Other In January 2017, the FASB issued ASU 2017-04, non-cash
Leases	Leases In February 2016, the FASB issued ASU 2016-02, right-of-use We anticipate this guidance will have a material impact on our consolidated financial statements. While we are continuing to assess all potential impacts of the new guidance, we currently believe the most significant impact relates to our real estate operating leases and the related recognition of right-of-use
Stock Compensation	Stock Compensation In March 2016, the FASB issued ASU No. 2016-09,
Cash Receipts and Cash Payments	Cash Receipts and Cash Payments In August 2016, the FASB issued ASU No. 2016-15, 2016-15). 2016-15
Consolidations	Consolidations In October 2016, the FASB issued ASU No. 2016-17, 2015-02,
Income Taxes	Income Taxes In October 2016, the FASB issued ASU No. 2016-16,
Restricted Cash	Restricted Cash In November 2016, the FASB issued Accounting Standards Update 2016-18,
Revenue Recognition	Revenue Recognition In May 2014, the FASB issued ASU No. 2014-09, pre-2018 A preliminary assessment to determine the impacts of the new accounting standard has been performed. We are currently implementing new accounting and operational processes which will be impacted by the new guidance, but we are unable to provide information on quantitative impacts at this time. We anticipate this standard will have a material impact on individual lines in our consolidated financial statements, but we do not expect it will have as material an impact on our results of operations on an annual basis. The primary impacts of the new standard to our product and service lines are anticipated to be as follows:
Segment Reporting	Brokerage segment Revenue Expense - Risk management segment We are currently assessing the timing and measurement of revenue recognition under the new guidance for our risk management segment, specifically third party administration contracts among others, and anticipate that more revenue will be initially deferred and recognized over a longer future period of time than under our current accounting policies. Corporate segment We expect that the timing related to recognition of revenue in our corporate segment will remain substantially unchanged.

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Acquisition Method for Recording Business Combinations	During the three-month period ended March 31, 2017, we acquired substantially all of the net assets of the following firms in exchange for our common stock and/or cash. These acquisitions have been accounted for using the acquisition method for recording business combinations (in millions except share data): Name and Effective Date of Acquisition Common Common Cash Paid Accrued Escrow Recorded Total Maximum (000s) Construction Risk Solutions, LLC (CRS) January 1, 2017 — $ — $ 27.9 $ — $ 3.1 $ 4.5 $ 35.5 $ 10.0 Hill, Chesson & Woody (HCW) January 1, 2017 — — 34.8 — 0.7 15.6 51.1 24.4 Presidio Group, Inc. (PG) January 1, 2017 — — 41.8 — 4.8 5.5 52.1 15.0 Nine other acquisitions completed in 2017 166 8.4 38.8 — 3.6 7.3 58.1 19.0 166 $ 8.4 $ 143.3 $ — $ 12.2 $ 32.9 $ 196.8 $ 68.4
Summary of Estimated Fair Values of Net Assets Acquired	The following is a summary of the estimated fair values of the net assets acquired at the date of each acquisition made in the three-month period ended March 31, 2017 (in millions): CRS HCW PG Nine Other Acquisitions Total Cash $ — $ — $ — $ 2.2 $ 2.2 Other current assets 3.6 2.1 2.4 3.0 11.1 Fixed assets — — 0.5 0.6 1.1 Noncurrent assets — 0.2 — — 0.2 Goodwill 12.3 26.2 25.0 28.4 91.9 Expiration lists 22.7 22.3 26.8 33.3 105.1 Non-compete 0.1 0.4 0.3 0.2 1.0 Total assets acquired 38.7 51.2 55.0 67.7 212.6 Current liabilities 3.2 0.1 2.9 4.1 10.3 Noncurrent liabilities — — — 5.5 5.5 Total liabilities assumed 3.2 0.1 2.9 9.6 15.8 Total net assets acquired $ 35.5 $ 51.1 $ 52.1 $ 58.1 $ 196.8
Summary of Unaudited Pro Forma Historical Results	The following is a summary of the unaudited pro forma historical results, as if these entities had been acquired at January 1, 2016 (in millions, except per share data): Three-month period ended March 31, 2017 2016 Total revenues $ 1,414.4 $ 1,317.2 Net earnings attributable to controlling interests 55.7 47.3 Basic net earnings per share 0.31 0.27 Diluted net earnings per share 0.31 0.27

Other Current Assets (Tables)

Other Current Assets (Tables)	3 Months Ended
	Mar. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Major Classes of Other Current Assets	Major classes of other current assets consist of the following (in millions): March 31, 2017 December 31, 2016 Premium finance advances and loans $ 220.1 $ 241.2 Accrued supplemental, direct bill and other receivables 170.9 177.2 Refined coal production related receivables 121.5 136.9 Prepaid expenses 81.9 78.4 Total other current assets $ 594.4 $ 633.7

Intangible Assets (Tables)

Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Carrying Amount of Goodwill Allocated by Domestic and Foreign Operations	The carrying amount of goodwill at March 31, 2017 and December 31, 2016 allocated by domestic and foreign operations is as follows (in millions): At March 31, 2017 Brokerage Risk Management Corporate Total United States $ 2,201.6 $ 23.5 $ — $ 2,225.1 United Kingdom 667.8 4.3 — 672.1 Canada 293.8 — — 293.8 Australia 410.9 — — 410.9 New Zealand 208.5 0.3 — 208.8 Other foreign 83.3 — 2.9 86.2 Total goodwill - net $ 3,865.9 $ 28.1 $ 2.9 $ 3,896.9 At December 31, 2016 United States $ 2,115.0 $ 23.5 $ — $ 2,138.5 United Kingdom 662.2 4.3 — 666.5 Canada 292.2 — — 292.2 Australia 382.7 — — 382.7 New Zealand 205.0 0.3 — 205.3 Other foreign 79.8 — 2.8 82.6 Total goodwill - net $ 3,736.9 $ 28.1 $ 2.8 $ 3,767.8
Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill for the three-month period ended March 31, 2017 are as follows (in millions): Brokerage Risk Management Corporate Total Balance as of December 31, 2016 $ 3,736.9 $ 28.1 $ 2.8 $ 3,767.8 Goodwill acquired during the period 91.9 — — 91.9 Goodwill adjustments due to appraisals and other acquisition adjustments 1.6 — — 1.6 Foreign currency translation adjustments during the period 35.5 — 0.1 35.6 Balance as of March 31, 2017 $ 3,865.9 $ 28.1 $ 2.9 $ 3,896.9
Major Classes of Amortizable Intangible Assets	Major classes of amortizable intangible assets at March 31, 2017 and December 31, 2016 consist of the following (in millions): March 31, 2017 December 31, 2016 Expiration lists $ 2,880.5 $ 2,757.6 Accumulated amortization - expiration lists (1,210.1 ) (1,143.0 ) 1,670.4 1,614.6 Non-compete 50.5 49.3 Accumulated amortization - non-compete (43.3 ) (42.1 ) 7.2 7.2 Trade names 24.4 24.0 Accumulated amortization - trade names (19.9 ) (18.5 ) 4.5 5.5 Net amortizable assets $ 1,682.1 $ 1,627.3
Estimated Aggregate Amortization Expense	Estimated aggregate amortization expense for each of the next five years is as follows: 2017 (remaining nine months) $ 190.8 2018 239.9 2019 225.8 2020 209.6 2021 187.2 Total $ 1,053.3

Credit and Other Debt Agreeme28

Credit and Other Debt Agreements (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Summary of Corporate and Other Debt	The following is a summary of our corporate and other debt (in millions): March 31, 2017 December 31, 2016 Note Purchase Agreements: Semi-annual payments of interest, fixed rate of 6.44%, balloon due August 3, 2017 $ 300.0 $ 300.0 Semi-annual payments of interest, fixed rate of 5.85%, $50 million due November 30, 2018 and November 30, 2019 100.0 100.0 Semi-annual payments of interest, fixed rate of 2.80%, balloon due June 24, 2018 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.20%, balloon due June 24, 2019 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.99%, balloon due July 10, 2020 50.0 50.0 Semi-annual payments of interest, fixed rate of 3.48%, balloon due June 24, 2020 50.0 50.0 Semi-annual payments of interest, fixed rate of 5.18%, balloon due February 10, 2021 75.0 75.0 Semi-annual payments of interest, fixed rate of 3.69%, balloon due June 14, 2022 200.0 200.0 Semi-annual payments of interest, fixed rate of 5.49%, balloon due February 10, 2023 50.0 50.0 Semi-annual payments of interest, fixed rate of 4.13%, balloon due June 24, 2023 200.0 200.0 Semi-annual payments of interest, fixed rate of 4.58%, balloon due February 27, 2024 325.0 325.0 Semi-annual payments of interest, fixed rate of 4.31%, balloon due June 24, 2025 200.0 200.0 Semi-annual payments of interest, fixed rate of 4.73%, balloon due February 27, 2026 175.0 175.0 Semi-annual payments of interest, fixed rate of 4.36%, balloon due June 24, 2026 150.0 150.0 Semi-annual payments of interest, fixed rate of 4.40%, balloon due June 2, 2026 175.0 175.0 Semi-annual payments of interest, fixed rate of 3.46%, balloon due December 1, 2027 100.0 100.0 Semi-annual payments of interest, fixed rate of 4.55%, balloon due June 2, 2028 75.0 75.0 Semi-annual payments of interest, fixed rate of 4.98%, balloon due February 27, 2029 100.0 100.0 Semi-annual payments of interest, fixed rate of 4.70%, balloon due June 2, 2031 25.0 25.0 Total Note Purchase Agreements 2,450.0 2,450.0 Credit Agreement: Periodic payments of interest and principal, prime or LIBOR plus up to 1.45%, expires April 8, 2021 395.0 278.0 Premium Financing Debt Facility - expires May 18, 2017: Periodic payments of interest and principal, Interbank rates plus 1.05% for Facility B; plus 0.55% for Facilities C and D Facility B AUD denominated tranche 66.4 100.7 NZD denominated tranche 8.4 9.0 Facility C and D AUD denominated tranche 19.2 5.6 NZD denominated tranche 10.4 10.3 Total Premium Financing Debt Facility 104.4 125.6 Total corporate and other debt 2,949.4 2,853.6 Less unamortized debt acquisition costs on Note Purchase Agreements (5.3 ) (5.4 ) Net corporate and other debt $ 2,944.1 $ 2,848.2

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net EPS	The following table sets forth the computation of basic and diluted net earnings per share (in millions, except per share data): Three-month period ended March 31, 2017 2016 Net earnings attributable to controlling interests $ 55.7 $ 46.5 Weighted average number of common shares outstanding 178.9 177.0 Dilutive effect of stock options using the treasury stock method 1.7 0.6 Weighted average number of common and common equivalent shares outstanding 180.6 177.6 Basic net earnings per share $ 0.31 $ 0.26 Diluted net earnings per share $ 0.31 $ 0.26

Stock Option Plans (Tables)

Stock Option Plans (Tables)	3 Months Ended
	Mar. 31, 2017
Text Block [Abstract]
Black-Scholes Option Pricing Model with Weighted Average	For purposes of expense recognition, the estimated fair values of the stock option grants are amortized to expense over the options’ vesting period. We estimated the fair value of stock options at the date of grant using the Black-Scholes option pricing model with the following weighted average assumptions: 2017 2016 Expected dividend yield 2.8 % 3.0 % Expected risk-free interest rate 2.3 % 1.6 % Volatility 27.2 % 27.7 % Expected life (in years) 5.0 5.5
Stock Option Activity and Related Information	The following is a summary of our stock option activity and related information for 2017 (in millions, except exercise price and year data): Three-month period ended March 31, 2017 Shares Under Option Weighted Average Exercise Price Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value Beginning balance 10.3 $ 41.40 Granted 1.6 56.86 Exercised (0.7 ) 30.98 Forfeited or canceled — — Ending balance 11.2 $ 44.35 4.53 $ 137.4 Exercisable at end of period 3.2 $ 37.28 2.38 $ 61.5 Ending vested and expected to vest 11.0 $ 44.26 4.50 $ 135.6
Other Information Regarding Stock Options Outstanding and Exercisable	Other information regarding stock options outstanding and exercisable at March 31, 2017 is summarized as follows (in millions, except exercise price and year data): Options Outstanding Options Exercisable Range of Exercise Prices Number Weighted (in years) Weighted Number Weighted $ 23.76 - $ 39.17 3.2 2.17 $ 35.68 2.6 $ 35.01 43.71 - 46.17 4.5 5.53 44.77 — — 46.87 - 49.55 1.9 3.97 46.89 0.6 46.87 56.86 - 56.86 1.6 6.96 56.86 — — $ 23.76 - $ 56.86 11.2 4.53 $ 44.35 3.2 $ 37.28

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investments Reported in Other Current and Non-Current Assets	The following is a summary of our investments, included in other noncurrent assets in the consolidated balance sheet, and the related funding commitments (in millions): March 31, 2017 December 31, Funding 2016 Assets Commitments Assets Chem-Mod LLC $ 4.0 $ — $ 4.0 Chem-Mod International LLC 2.0 — 2.0 Clean-coal investments: Controlling interest in six limited liability companies that own fourteen 2009 Era Clean Coal Plants 13.3 — 14.3 Non-controlling 0.7 — 0.7 Controlling interest in seventeen limited liability companies that own nineteen 2011 Era Clean Coal Plants 69.5 — 69.0 Other investments 3.8 0.4 3.7 Total investments $ 93.3 $ 0.4 $ 93.7

Derivatives and Hedging Activ32

Derivatives and Hedging Activity (Tables)	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Notional and Fair Values of Derivative Instruments	The notional and fair values of derivative instruments are as follows at March 31, 2017 and December 31, 2016 (in millions): Notional Amount Derivatives Assets (1) Derivative Liabilities (2) March 31, 2017 Dec 31, 2016 March 31, 2017 Dec 31, 2016 March 31, 2017 Dec 31, 2016 Derivatives accounted for as hedges: Interest rate contracts $ 250.0 $ 200.0 $ 12.2 $ 11.4 $ — $ — Foreign exchange contracts (3) 6.2 4.1 5.2 2.1 12.8 17.5 Total $ 256.2 $ 204.1 $ 17.4 $ 13.5 $ 12.8 $ 17.5 (1) Included within other current assets, $15.0 million and $12.5 million at March 31, 2017 and December 31, 2016, respectively, and other non-current (2) Included within other current liabilities, $8.9 million and $11.8 million at March 31, 2017 and December 31, 2016, respectively, and other non-current (3) Included within foreign exchange contracts at March 31, 2017 were $95.5 million of call options offset with $95.5 million of put options, and $46.9 million of buy forwards offset with $53.1 million of sell forwards. Included within foreign exchange contracts at December 31, 2016 were $78.3 million of call options offset with $78.3 million of put options, and $61.6 million of buy forwards offset with $57.5 million of sell forwards.
Summary of Amounts of Derivative Gains (Losses) Recognized In Accumulated Other Comprehensive Loss	The amounts of derivative gains (losses) recognized in accumulated other comprehensive loss were as follows (in millions): Commission Compensation Operating Interest Total March 31, 2017 Cash flow hedges: Interest rate contracts $ — $ — $ — $ 0.8 $ 0.8 Foreign exchange contracts 2.4 1.8 1.2 — 5.4 Total $ 2.4 $ 1.8 $ 1.2 $ 0.8 $ 6.2 March 31, 2016 Cash flow hedges: Interest rate contracts $ — $ — $ — $ 1.1 $ 1.1 Foreign exchange contracts (3.4 ) — — — (3.4 ) Total $ (3.4 ) $ — $ — $ 1.1 $ (2.3 ) The amounts of derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion) were as follows (in millions): Commission Revenue Compensation Expense Operating Expense Interest Expense Total March 31, 2017 Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts (2.8 ) 0.2 0.2 — (2.4 ) Total $ (2.8 ) $ 0.2 $ 0.2 $ — $ (2.4 ) March 31, 2016 Cash flow hedges: Interest rate contracts $ — $ — $ — $ — $ — Foreign exchange contracts (1.2 ) — — — (1.2 ) Total $ (1.2 ) $ — $ — $ — $ (1.2 )

Commitments, Contingencies an33

Commitments, Contingencies and Off-Balance Sheet Arrangements (Tables)	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contractual Obligations	Our future minimum cash payments, including interest, associated with our contractual obligations pursuant to the note purchase agreements, Credit Agreement, Premium Financing Debt Facility, operating leases and purchase commitments at March 31, 2017 were as follows (in millions): Payments Due by Period Contractual Obligations 2017 2018 2019 2020 2021 Thereafter Total Note purchase agreements $ 300.0 $ 100.0 $ 100.0 $ 100.0 $ 75.0 $ 1,775.0 $ 2,450.0 Credit Agreement 395.0 — — — — — 395.0 Premium Financing Debt Facility 104.4 — — — — — 104.4 Interest on debt 85.4 92.9 88.9 84.3 79.4 280.5 711.4 Total debt obligations 884.8 192.9 188.9 184.3 154.4 2,055.5 3,660.8 Operating lease obligations 79.0 88.7 73.3 60.7 50.3 121.5 473.5 Less sublease arrangements (0.8 ) (0.4 ) (0.1 ) (0.1 ) — — (1.4 ) Outstanding purchase obligations 42.3 32.3 17.3 7.3 2.2 — 101.4 Total contractual obligations $ 1,005.3 $ 313.5 $ 279.4 $ 252.2 $ 206.9 $ 2,177.0 $ 4,234.3
Off-Balance Sheet Commitments	Our total unrecorded commitments associated with outstanding letters of credit, financial guarantees and funding commitments as of March 31, 2017 were as follows (in millions): Amount of Commitment Expiration by Period Total Amounts Committed Off-Balance 2017 2018 2019 2020 2021 Thereafter Letters of credit $ — $ — $ — $ — $ — $ 21.1 $ 21.1 Financial guarantees 0.1 0.2 0.2 0.2 0.2 1.4 2.3 Funding commitments — — — — — 0.4 0.4 Total commitments $ 0.1 $ 0.2 $ 0.2 $ 0.2 $ 0.2 $ 22.9 $ 23.8

Accumulated Other Comprehensi34

Accumulated Other Comprehensive Earnings (Loss) (Tables)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Earnings (Loss) Attributable to Controlling Interests	The after-tax Pension Liability Foreign Currency Translation Fair Value of Derivative Investments Accumulated Comprehensive Earnings (Loss) Balance as of December 31, 2016 $ (47.3 ) $ (709.2 ) $ (7.1 ) $ (763.6 ) Net change in period 1.2 56.8 6.5 64.5 Balance as of March 31, 2017 $ (46.1 ) $ (652.4 ) $ (0.6 ) $ (699.1 )

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Schedule of Segment Reporting Information by Segment	Financial information relating to our segments for the three-month periods ended March 31, 2017 and 2016 is as follows (in millions): Three -month ended March 31, 2017 2016 Brokerage Total revenues $ 878.5 $ 825.5 Earnings before income taxes $ 117.7 $ 100.0 Identifiable assets at March 31, 2017 and 2016 $ 9,422.9 $ 8,681.9 Risk Management Total revenues $ 182.6 $ 179.3 Earnings before income taxes $ 22.9 $ 24.0 Identifiable assets at March 31, 2017 and 2016 $ 691.1 $ 690.4 Corporate Total revenues $ 351.6 $ 295.6 Loss before income taxes $ (88.3 ) $ (68.3 ) Identifiable assets at March 31, 2017 and 2016 $ 1,666.9 $ 1,340.3

Nature of Operations and Basi36

Nature of Operations and Basis of Presentation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2017CountrySegment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of countries in which the company has operations	33
Number of countries in which the company does business through a network of correspondent brokers and consultants	150
Number of reportable segments | Segment	3

Effect of New Accounting Pron37

Effect of New Accounting Pronouncements - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax benefit recognized	$ (15.5)	$ (2.2)
Reclassification of payments from investing activities to operating activities	169.7	100
Reclassification of payments from investing activities to financing activities	19.9	(41.9)
Restatement Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of payments from investing activities to operating activities	9.4
Reclassification of payments from investing activities to financing activities	7.8
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax benefit recognized	$ 8.2	$ 0.6

Business Combinations - Acquisi

Business Combinations - Acquisition Method for Recording Business Combinations (Detail) shares in Thousands	3 Months Ended
	Mar. 31, 2017USD ($)shares
Business Acquisition [Line Items]
Common Shares Issued | shares	166
Common Share Value	$ 8,400,000
Cash Paid	143,300,000
Accrued Liability	0
Escrow Deposited	12,200,000
Recorded Earnout Payable	32,900,000
Total Recorded Purchase Price	196,800,000
Maximum Potential Earnout Payable	68,400,000
Construction Risk Solutions, LLC [Member]
Business Acquisition [Line Items]
Cash Paid	27,900,000
Accrued Liability	0
Escrow Deposited	3,100,000
Recorded Earnout Payable	4,500,000
Total Recorded Purchase Price	35,500,000
Maximum Potential Earnout Payable	10,000,000
Hill, Chesson And Woody [Member]
Business Acquisition [Line Items]
Cash Paid	34,800,000
Accrued Liability	0
Escrow Deposited	700,000
Recorded Earnout Payable	15,600,000
Total Recorded Purchase Price	51,100,000
Maximum Potential Earnout Payable	24,400,000
Presidio Group, Inc. [Member]
Business Acquisition [Line Items]
Cash Paid	41,800,000
Accrued Liability	0
Escrow Deposited	4,800,000
Recorded Earnout Payable	5,500,000
Total Recorded Purchase Price	52,100,000
Maximum Potential Earnout Payable	$ 15,000,000
Nine Other Acquisitions [Member]
Business Acquisition [Line Items]
Common Shares Issued | shares	166
Common Share Value	$ 8,400,000
Cash Paid	38,800,000
Accrued Liability	0
Escrow Deposited	3,600,000
Recorded Earnout Payable	7,300,000
Total Recorded Purchase Price	58,100,000
Maximum Potential Earnout Payable	$ 19,000,000

Business Combinations - Acqui39

Business Combinations - Acquisition Method for Recording Business Combinations (Parenthetical) (Detail)	3 Months Ended
	Mar. 31, 2017
Construction Risk Solutions, LLC [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Jan. 1, 2017
Hill, Chesson And Woody [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Jan. 1, 2017
Presidio Group, Inc. [Member]
Business Acquisition [Line Items]
Effective Date of Acquisition	Jan. 1, 2017
Nine Other Acquisitions [Member]
Business Acquisition [Line Items]
Effective Year of Acquisition	2,017

Business Combinations - Additio

Business Combinations - Additional Information (Detail)	3 Months Ended		183 Months Ended
	Mar. 31, 2017USD ($)Entity	Mar. 31, 2016USD ($)Entity	Mar. 31, 2017USD ($)Entity
Business Acquisition [Line Items]
Accretion of the discount on acquisition	$ 5,100,000	$ 4,200,000
Number of companies acquired | Entity	40	32	432
Aggregate amount of maximum earnout obligations related to acquisitions	$ 565,300,000
Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet	268,300,000
Income (expense) related to net adjustments to estimated fair value of liability for earnout obligations	(6,700,000)	$ 300,000
Goodwill	91,900,000		$ 91,900,000
Expiration lists	105,100,000		105,100,000
Non-compete agreements	1,000,000		1,000,000
Total revenues related to acquisitions in the aggregate	1,414,400,000	$ 1,317,200,000
Brokerage and Risk Management [Member]
Business Acquisition [Line Items]
Goodwill	91,900,000		91,900,000
Expiration lists	105,100,000		105,100,000
Non-compete agreements	$ 1,000,000		1,000,000
Expiration Lists [Member] | Minimum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years	3 years
Expiration Lists [Member] | Maximum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years	15 years
Non-Compete Agreements [Member] | Minimum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years	3 years
Non-Compete Agreements [Member] | Maximum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years	5 years
Trade Names [Member] | Minimum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years	3 years
Trade Names [Member] | Maximum [Member]
Business Acquisition [Line Items]
Estimated useful lives of intangibles assets, years	5 years
2017 Acquisitions [Member] | Market Approach Valuation Technique [Member] | Minimum [Member]
Business Acquisition [Line Items]
Revenue growth rate	5.00%
Discount rate	8.50%
2017 Acquisitions [Member] | Market Approach Valuation Technique [Member] | Maximum [Member]
Business Acquisition [Line Items]
Revenue growth rate	15.00%
Discount rate	9.00%
2016 Acquisitions [Member] | Income Approach Valuation Technique [Member] | Minimum [Member]
Business Acquisition [Line Items]
Revenue growth rate	3.00%
Discount rate	12.00%
Attrition rate	3.30%
2016 Acquisitions [Member] | Income Approach Valuation Technique [Member] | Maximum [Member]
Business Acquisition [Line Items]
Revenue growth rate	5.50%
Discount rate	12.20%
Attrition rate	7.30%
Business Acquisition [Member]
Business Acquisition [Line Items]
Annualized revenue of business acquisitions	$ 62,500,000
Total revenues related to acquisitions in the aggregate	14,800,000
Net earnings	500,000
Business Acquisition [Member] | Brokerage [Member]
Business Acquisition [Line Items]
Expiration lists	105,100,000		105,100,000
Non-compete agreements	1,000,000		1,000,000
Deferred tax liability	5,400,000		5,400,000
Goodwill related to nondeductible amortizable intangible assets	5,400,000
Business Acquisition [Member] | Expiration Lists [Member] | Brokerage [Member]
Business Acquisition [Line Items]
Business acquisition not deductible for income tax purposes	16,100,000		16,100,000
Business Acquisition [Member] | Non-Compete Agreements [Member] | Brokerage [Member]
Business Acquisition [Line Items]
Business acquisition not deductible for income tax purposes	$ 100,000		$ 100,000

Business Combinations - Summary

Business Combinations - Summary of Estimated Fair Values of Net Assets Acquired (Detail) $ in Millions	Mar. 31, 2017USD ($)
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	$ 2.2
Other current assets	11.1
Fixed assets	1.1
Noncurrent assets	0.2
Goodwill	91.9
Expiration lists	105.1
Non-compete agreements	1
Total assets acquired	212.6
Current liabilities	10.3
Noncurrent liabilities	5.5
Total liabilities assumed	15.8
Total net assets acquired	196.8
Construction Risk Solutions, LLC [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Other current assets	3.6
Goodwill	12.3
Expiration lists	22.7
Non-compete agreements	0.1
Total assets acquired	38.7
Current liabilities	3.2
Total liabilities assumed	3.2
Total net assets acquired	35.5
Hill, Chesson And Woody [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Other current assets	2.1
Noncurrent assets	0.2
Goodwill	26.2
Expiration lists	22.3
Non-compete agreements	0.4
Total assets acquired	51.2
Current liabilities	0.1
Total liabilities assumed	0.1
Total net assets acquired	51.1
Presidio Group, Inc. [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Other current assets	2.4
Fixed assets	0.5
Goodwill	25
Expiration lists	26.8
Non-compete agreements	0.3
Total assets acquired	55
Current liabilities	2.9
Total liabilities assumed	2.9
Total net assets acquired	52.1
Nine Other Acquisitions [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Cash	2.2
Other current assets	3
Fixed assets	0.6
Goodwill	28.4
Expiration lists	33.3
Non-compete agreements	0.2
Total assets acquired	67.7
Current liabilities	4.1
Noncurrent liabilities	5.5
Total liabilities assumed	9.6
Total net assets acquired	$ 58.1

Business Combinations - Summa42

Business Combinations - Summary of Unaudited Pro Forma Historical Results (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Business Combinations [Abstract]
Total revenues	$ 1,414.4	$ 1,317.2
Net earnings attributable to controlling interests	$ 55.7	$ 47.3
Basic net earnings per share	$ 0.31	$ 0.27
Diluted net earnings per share	$ 0.31	$ 0.27

Other Current Assets - Summary

Other Current Assets - Summary of Major Classes of Other Current Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Premium finance advances and loans	$ 220.1	$ 241.2
Accrued supplemental, direct bill and other receivables	170.9	177.2
Refined coal production related receivables	121.5	136.9
Prepaid expenses	81.9	78.4
Total other current assets	$ 594.4	$ 633.7

Other Current Assets - Addition

Other Current Assets - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Collateralized delinquency period of receivables	7 days

Intangible Assets - Carrying Am

Intangible Assets - Carrying Amount of Goodwill Allocated by Domestic and Foreign Operations (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Goodwill [Line Items]
Total goodwill - net	$ 3,896.9	$ 3,767.8
Unites States [Member]
Goodwill [Line Items]
Total goodwill - net	2,225.1	2,138.5
United Kingdom [Member]
Goodwill [Line Items]
Total goodwill - net	672.1	666.5
Canada [Member]
Goodwill [Line Items]
Total goodwill - net	293.8	292.2
Australia [Member]
Goodwill [Line Items]
Total goodwill - net	410.9	382.7
New Zealand [Member]
Goodwill [Line Items]
Total goodwill - net	208.8	205.3
Other Foreign [Member]
Goodwill [Line Items]
Total goodwill - net	86.2	82.6
Brokerage [Member]
Goodwill [Line Items]
Total goodwill - net	3,865.9	3,736.9
Brokerage [Member] | Unites States [Member]
Goodwill [Line Items]
Total goodwill - net	2,201.6	2,115
Brokerage [Member] | United Kingdom [Member]
Goodwill [Line Items]
Total goodwill - net	667.8	662.2
Brokerage [Member] | Canada [Member]
Goodwill [Line Items]
Total goodwill - net	293.8	292.2
Brokerage [Member] | Australia [Member]
Goodwill [Line Items]
Total goodwill - net	410.9	382.7
Brokerage [Member] | New Zealand [Member]
Goodwill [Line Items]
Total goodwill - net	208.5	205
Brokerage [Member] | Other Foreign [Member]
Goodwill [Line Items]
Total goodwill - net	83.3	79.8
Risk Management [Member]
Goodwill [Line Items]
Total goodwill - net	28.1	28.1
Risk Management [Member] | Unites States [Member]
Goodwill [Line Items]
Total goodwill - net	23.5	23.5
Risk Management [Member] | United Kingdom [Member]
Goodwill [Line Items]
Total goodwill - net	4.3	4.3
Risk Management [Member] | New Zealand [Member]
Goodwill [Line Items]
Total goodwill - net	0.3	0.3
Corporate [Member]
Goodwill [Line Items]
Total goodwill - net	2.9	2.8
Corporate [Member] | Other Foreign [Member]
Goodwill [Line Items]
Total goodwill - net	$ 2.9	$ 2.8

Intangible Assets - Changes in

Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Goodwill [Line Items]
Beginning Balance	$ 3,767.8
Goodwill acquired during the period	91.9
Goodwill adjustments due to appraisals and other acquisition adjustments	1.6
Foreign currency translation adjustments during the period	35.6
Balance as of March 31, 2017	3,896.9
Brokerage [Member]
Goodwill [Line Items]
Beginning Balance	3,736.9
Goodwill acquired during the period	91.9
Goodwill adjustments due to appraisals and other acquisition adjustments	1.6
Foreign currency translation adjustments during the period	35.5
Balance as of March 31, 2017	3,865.9
Risk Management [Member]
Goodwill [Line Items]
Beginning Balance	28.1
Balance as of March 31, 2017	28.1
Corporate [Member]
Goodwill [Line Items]
Beginning Balance	2.8
Foreign currency translation adjustments during the period	0.1
Balance as of March 31, 2017	$ 2.9

Intangible Assets - Major Class

Intangible Assets - Major Classes of Amortizable Intangible Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, net	$ 1,682.1	$ 1,627.3
Expiration Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	2,880.5	2,757.6
Accumulated amortization	(1,210.1)	(1,143)
Amortizable intangible assets, net	1,670.4	1,614.6
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	50.5	49.3
Accumulated amortization	(43.3)	(42.1)
Amortizable intangible assets, net	7.2	7.2
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	24.4	24
Accumulated amortization	(19.9)	(18.5)
Amortizable intangible assets, net	$ 4.5	$ 5.5

Intangible Assets - Estimated A

Intangible Assets - Estimated Aggregate Amortization Expense (Detail) $ in Millions	Mar. 30, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2017 (remaining nine months)	$ 190.8
2,018	239.9
2,019	225.8
2,020	209.6
2,021	187.2
Total	$ 1,053.3

Credit and Other Debt Agreeme49

Credit and Other Debt Agreements - Summary of Corporate and Other Debt (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Semi-annual payments of interest	$ 2,949.4	$ 2,853.6
Less unamortized debt acquisition costs on Note Purchase Agreements	(5.3)	(5.4)
Semi-annual payments of interest, Net	2,944.1	2,848.2
Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	104.4	125.6
Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	2,450	2,450
Fixed Rate of 6.44%, Balloon Due August 3, 2017 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	300	300
Fixed Rate of 5.85%, $50 Million Due November 30, 2018 and November 30, 2019 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	100	100
Fixed Rate of 2.80%, Balloon Due June 24, 2018 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	50	50
Fixed Rate of 3.20%, Balloon Due June 24, 2019 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	50	50
Fixed Rate of 3.99%, Balloon Due July 10, 2020 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	50	50
Fixed Rate of 3.48%, Balloon Due June 24, 2020 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	50	50
Fixed Rate of 5.18%, Balloon Due February 10, 2021 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	75	75
Fixed Rate of 3.69%, Balloon Due June 14, 2022 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	200	200
Fixed Rate of 5.49%, Balloon Due February 10, 2023 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	50	50
Fixed Rate of 4.13%, Balloon Due June 24, 2023 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	200	200
Fixed Rate of 4.58%, Balloon Due February 27, 2024 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	325	325
Fixed Rate of 4.31%, Balloon Due June 24, 2025 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	200	200
Fixed Rate of 4.73%, Balloon Due February 27, 2026 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	175	175
Fixed Rate of 4.36%, Balloon Due June 24, 2026 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	150	150
Fixed Rate of 4.40%, Balloon Due June 2, 2026 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	175	175
Fixed Rate of 3.46%, Balloon Due December 1, 2027 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	100	100
Fixed Rate of 4.55%, Balloon Due June 2, 2028 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	75	75
Fixed Rate of 4.98%, Balloon Due February 27, 2029 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	100	100
Fixed Rate of 4.70%, Balloon Due June 2, 2031 [Member] | Note Purchase Agreements [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	25	25
Prime or LIBOR plus up to 1.45%, expires April 8, 2016 [Member] | Multi Currency Credit Agreement [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	395	278
Interbank rates plus 1.05%, Expires May 18, 2017 [Member] | AUD denominated tranche [Member] | Facility B [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	66.4	100.7
Interbank rates plus 1.05%, Expires May 18, 2017 [Member] | NZD denominated tranche [Member] | Facility B [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	8.4	9
Interbank rates plus 0.55%, Expires May 18, 2017 [Member] | AUD denominated tranche [Member] | Facility C and D [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	19.2	5.6
Interbank rates plus 0.55%, Expires May 18, 2017 [Member] | NZD denominated tranche [Member] | Facility C and D [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Semi-annual payments of interest	$ 10.4	$ 10.3

Credit and Other Debt Agreeme50

Credit and Other Debt Agreements - Summary of Corporate and Other Debt (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Periodic payments of interest and principal, expiry date	May 18, 2017	May 18, 2017
Fixed Rate of 6.44%, Balloon Due August 3, 2017 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	6.44%	6.44%
Periodic payments of interest and principal, expiry date	Aug. 3, 2017	Aug. 3, 2017
Fixed Rate of 5.85%, $50 Million Due November 30, 2018 and November 30, 2019 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	5.85%	5.85%
Long-Term debt maturities repayments in 2018	$ 50	$ 50
Long-Term debt maturities repayments in 2019	$ 50	$ 50
Fixed Rate of 2.80%, Balloon Due June 24, 2018 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	2.80%	2.80%
Periodic payments of interest and principal, expiry date	Jun. 24, 2018	Jun. 24, 2018
Fixed Rate of 3.20%, Balloon Due June 24, 2019 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	3.20%	3.20%
Periodic payments of interest and principal, expiry date	Jun. 24, 2019	Jun. 24, 2019
Fixed Rate of 3.99%, Balloon Due July 10, 2020 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	3.99%	3.99%
Periodic payments of interest and principal, expiry date	Jul. 10, 2020	Jul. 10, 2020
Fixed Rate of 3.48%, Balloon Due June 24, 2020 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	3.48%	3.48%
Periodic payments of interest and principal, expiry date	Jun. 24, 2020	Jun. 24, 2020
Fixed Rate of 5.18%, Balloon Due February 10, 2021 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	5.18%	5.18%
Periodic payments of interest and principal, expiry date	Feb. 10, 2021	Feb. 10, 2021
Fixed Rate of 3.69%, Balloon Due June 14, 2022 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	3.69%	3.69%
Periodic payments of interest and principal, expiry date	Jun. 14, 2022	Jun. 14, 2022
Fixed Rate of 5.49%, Balloon Due February 10, 2023 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	5.49%	5.49%
Periodic payments of interest and principal, expiry date	Feb. 10, 2023	Feb. 10, 2023
Fixed Rate of 4.13%, Balloon Due June 24, 2023 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.13%	4.13%
Periodic payments of interest and principal, expiry date	Jun. 24, 2023	Jun. 24, 2023
Fixed Rate of 4.58%, Balloon Due February 27, 2024 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.58%	4.58%
Periodic payments of interest and principal, expiry date	Feb. 27, 2024	Feb. 27, 2024
Fixed Rate of 4.31%, Balloon Due June 24, 2025 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.31%	4.31%
Periodic payments of interest and principal, expiry date	Jun. 24, 2025	Jun. 24, 2025
Fixed Rate of 4.73%, Balloon Due February 27, 2026 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.73%	4.73%
Periodic payments of interest and principal, expiry date	Feb. 27, 2026	Feb. 27, 2026
Fixed Rate of 4.36%, Balloon Due June 24, 2026 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.36%	4.36%
Periodic payments of interest and principal, expiry date	Jun. 24, 2026	Jun. 24, 2026
Fixed Rate of 4.40%, Balloon Due June 2, 2026 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.40%	4.40%
Periodic payments of interest and principal, expiry date	Jun. 2, 2026	Jun. 2, 2026
Fixed Rate of 3.46%, Balloon Due December 1, 2027 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	3.46%	3.46%
Periodic payments of interest and principal, expiry date	Dec. 1, 2027	Dec. 1, 2027
Fixed Rate of 4.55%, Balloon Due June 2, 2028 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.55%	4.55%
Periodic payments of interest and principal, expiry date	Jun. 2, 2028	Jun. 2, 2028
Fixed Rate of 4.98%, Balloon Due February 27, 2029 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.98%	4.98%
Periodic payments of interest and principal, expiry date	Feb. 27, 2029	Feb. 27, 2029
Fixed Rate of 4.70%, Balloon Due June 2, 2031 [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	4.70%	4.70%
Periodic payments of interest and principal, expiry date	Jun. 2, 2031	Jun. 2, 2031
Prime or LIBOR plus up to 1.45%, expires April 8, 2016 [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	1.45%	1.45%
Periodic payments of interest and principal, expiry date	Apr. 8, 2016	Apr. 8, 2016
First Installment [Member] | Fixed Rate of 5.85%, $50 Million Due November 30, 2018 and November 30, 2019 [Member]
Debt Instrument [Line Items]
Periodic payments of interest and principal, expiry date	Nov. 30, 2018	Nov. 30, 2018
Second Installment [Member] | Fixed Rate of 5.85%, $50 Million Due November 30, 2018 and November 30, 2019 [Member]
Debt Instrument [Line Items]
Periodic payments of interest and principal, expiry date	Nov. 30, 2019	Nov. 30, 2019
Facility B [Member] | Interbank rates plus 1.05%, Expires May 18, 2017 [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	1.05%	1.05%
Facility C and D [Member] | Interbank rates plus 0.55%, Expires May 18, 2017 [Member] | Premium Financing Debt Facility [Member]
Debt Instrument [Line Items]
Periodic Payment of Interest	0.55%	0.55%

Earnings Per Share - Computatio

Earnings Per Share - Computation of Basic and Diluted Net EPS (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Net earnings attributable to controlling interests	$ 55.7	$ 46.5
Weighted average number of common shares outstanding	178.9	177
Dilutive effect of stock options using the treasury stock method	1.7	0.6
Weighted average number of common and common equivalent shares outstanding	180.6	177.6
Basic net earnings per share	$ 0.31	$ 0.26
Diluted net earnings per share	$ 0.31	$ 0.26

Earnings Per Share - Additional

Earnings Per Share - Additional information (Detail) - shares shares in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Options to purchase common stock shares outstanding	0.3	4.3

Stock Option Plans - Additional

Stock Option Plans - Additional information (Detail) - USD ($)	Mar. 16, 2017	Mar. 17, 2016	Mar. 31, 2017	Mar. 31, 2016
Stock Option Plans [Line Items]
Compensation expense related to stock option grants			$ 4,100,000	$ 3,300,000
Total intrinsic value of options exercised			16,600,000	$ 1,700,000
Total unrecognized compensation cost related to nonvested options			$ 56,300,000
Weighted average period, years			4 years
Long Term Incentive Plan [Member]
Stock Option Plans [Line Items]
Maximum number of shares available			400,000
Shares available for grant			2,300,000
Long Term Incentive Plan [Member] | Officer and Key Employees [Member]
Stock Option Plans [Line Items]
Shares available for grant	1,650,400	2,576,700
Stock options granted, exercise percentage, on the third anniversary date of the grant	34.00%	34.00%
Stock options granted, exercise percentage, on the fourth anniversary date of the grant	33.00%	33.00%
Stock options granted, exercise percentage, on the fifth anniversary date of the grant	33.00%	33.00%
Long Term Incentive Plan [Member] | Maximum [Member]
Stock Option Plans [Line Items]
Maximum period for the exercise of stock options, years			7 years
Long Term Incentive Plan [Member] | Minimum [Member]
Stock Option Plans [Line Items]
Minimum exercise price of stock options, percent of fair market value of a share of common stock on the date of grant			100.00%
Period of service from grant date stock options awarded not subject to forfeiture			2 years	2 years
Long Term Incentive Plan [Member] | Minimum [Member] | Executive Officer [Member]
Stock Option Plans [Line Items]
Minimum age of employee with not subject to award forfeiture on condition compliance			55 years	55 years
Performance-Based Restricted Stock [Member]
Stock Option Plans [Line Items]
Maximum number of shares granted during any fiscal year to any person			100,000
Options or Stock Appreciation Rights [Member]
Stock Option Plans [Line Items]
Maximum number of shares granted during any fiscal year to any person			200,000
Cash Settled Performance Shares [Member] | Performance-Based Restricted Stock [Member]
Stock Option Plans [Line Items]
Maximum amount payable for the shares granted during any fiscal year to any person			$ 5,000,000
Stock Settled Performance Shares [Member] | Performance-Based Restricted Stock [Member]
Stock Option Plans [Line Items]
Maximum number of shares granted during any fiscal year to any person			100,000
Black-Scholes Option Pricing Model [Member]
Stock Option Plans [Line Items]
Weighted average fair value per option for all options			$ 11.42	$ 8.45

Stock Option Plans - Black-Scho

Stock Option Plans - Black-Scholes Option Pricing Model with Weighted Average (Detail)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected dividend yield	2.80%	3.00%
Expected risk-free interest rate	2.30%	1.60%
Volatility	27.20%	27.70%
Expected life (in years)	5 years	5 years 6 months

Stock Option Plans - Stock Opti

Stock Option Plans - Stock Option Activity and Related Information (Detail) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares Under Option, Beginning balance | shares	10.3
Shares Under Option, Granted | shares	1.6
Shares Under Option, Exercised | shares	(0.7)
Shares Under Option, Forfeited or canceled | shares	0
Shares Under Option, Ending balance | shares	11.2
Shares Under Option, Exercisable at end of period | shares	3.2
Shares Under Option, Ending vested and expected to vest | shares	11
Weighted Average Exercise Price, Beginning balance | $ / shares	$ 41.40
Weighted Average Exercise Price, Granted | $ / shares	56.86
Weighted Average Exercise Price, Exercised | $ / shares	30.98
Weighted Average Exercise Price, Forfeited or canceled | $ / shares	0
Weighted Average Exercised Price, Ending balance | $ / shares	44.35
Weighted Average Exercise Price, Exercisable at end of period | $ / shares	37.28
Weighted Average Exercise price, Ending vested and expected to vest | $ / shares	$ 44.26
Weighted Average Remaining Contractual Term (in years), Ending balance	4 years 6 months 11 days
Weighted Average Remaining Contractual Term (in years), Exercisable at end of period	2 years 4 months 17 days
Weighted Average Remaining Contractual Term (in years), Ending vested and expected to vest	4 years 6 months
Aggregate Intrinsic Value, Ending Balance | $	$ 137.4
Aggregate Intrinsic Value, Exercisable at end of period | $	61.5
Aggregate Intrinsic Value, Ending vested and expected to vest | $	$ 135.6

Stock Option Plans - Stock Op56

Stock Option Plans - Stock Options Outstanding and Exercisable (Detail) - $ / shares shares in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	$ 23.76
Range of Exercise Prices, maximum	$ 56.86
Option Outstanding, Number Outstanding	11.2
Option Outstanding, Weighted Average Remaining Contractual Term (in years)	4 years 6 months 11 days
Option Outstanding, Weighted Average Exercise Price	$ 44.35	$ 41.40
Options Exercisable, Number Exercisable	3.2
Option Exercisable, Weighted Average Exercise Price	$ 37.28
Exercise Prices Range $ 23.76 - $ 39.17 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	23.76
Range of Exercise Prices, maximum	$ 39.17
Option Outstanding, Number Outstanding	3.2
Option Outstanding, Weighted Average Remaining Contractual Term (in years)	2 years 2 months 1 day
Option Outstanding, Weighted Average Exercise Price	$ 35.68
Options Exercisable, Number Exercisable	2.6
Option Exercisable, Weighted Average Exercise Price	$ 35.01
Exercise Prices Range $ 43.71 - $ 46.17 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	43.71
Range of Exercise Prices, maximum	$ 46.17
Option Outstanding, Number Outstanding	4.5
Option Outstanding, Weighted Average Remaining Contractual Term (in years)	5 years 6 months 11 days
Option Outstanding, Weighted Average Exercise Price	$ 44.77
Exercise Prices Range $ 46.87 - $ 49.55 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	46.87
Range of Exercise Prices, maximum	$ 49.55
Option Outstanding, Number Outstanding	1.9
Option Outstanding, Weighted Average Remaining Contractual Term (in years)	3 years 11 months 19 days
Option Outstanding, Weighted Average Exercise Price	$ 46.89
Options Exercisable, Number Exercisable	0.6
Option Exercisable, Weighted Average Exercise Price	$ 46.87
Exercise Prices Range $ 56.86 - $ 56.86 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, minimum	56.86
Range of Exercise Prices, maximum	$ 56.86
Option Outstanding, Number Outstanding	1.6
Option Outstanding, Weighted Average Remaining Contractual Term (in years)	6 years 11 months 16 days
Option Outstanding, Weighted Average Exercise Price	$ 56.86

Deferred Compensation - Additio

Deferred Compensation - Additional information (Detail) - USD ($) shares in Millions	3 Months Ended			12 Months Ended
	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016
Investments And Employee Deferred Compensation Plan [Line Items]
Deferred Equity Participation Plan, distributions to key executives, age				Age 62 (or the one-year anniversary of the date of the grant for participants over the age of 61 as of the grant date) or upon or after their actual retirement.
Deferred Equity Participation Sub-plans, distributions to key executives, age				Age 65
Deferred Equity Participation Sub-plans, distributions requisite service description				We made awards under sub-plans of the DEPP for certain production staff, which generally provide for vesting and/or distributions no sooner than five years from the date of awards, although certain awards vest and/or distribute after the earlier of fifteen years or the participant reaching age 65.
Deferred Equity Participation Plan (DEPP) [Member]
Investments And Employee Deferred Compensation Plan [Line Items]
Awards approved by committee, value	$ 14,000,000		$ 10,100,000
Charge to compensation expenses related to awards	1,800,000		1,400,000
Cash and equity awards with aggregate fair value vested and distributed to participants	0		4,900,000
Unearned deferred compensation, value	$ 66,400,000			$ 46,800,000
Unearned deferred compensation, shares	2.7			2.4
Total intrinsic value of unvested equity based awards	$ 153,700,000			$ 125,500,000
Deferred Cash Participation Plan (DCPP) [Member]
Investments And Employee Deferred Compensation Plan [Line Items]
Awards approved by committee, value	5,100,000		3,100,000
Charge to compensation expenses related to awards	400,000		300,000
Cash and equity awards with aggregate fair value vested and distributed to participants	0		$ 0
Deferred Equity Participation Plan Sub Plans [Member]
Investments And Employee Deferred Compensation Plan [Line Items]
Awards approved by committee, value		$ 13,600,000
Charge to compensation expenses related to awards	400,000
Cash and equity awards with aggregate fair value vested and distributed to participants	$ 0

Restricted Stock, Performance58

Restricted Stock, Performance Share and Cash Awards - Additional Information (Detail)	Mar. 16, 2017USD ($)shares	Mar. 17, 2016USD ($)shares	Mar. 31, 2017USD ($)Timesshares	Mar. 31, 2016USD ($)shares	Dec. 31, 2016USD ($)shares	Mar. 31, 2015shares	Mar. 11, 2015USD ($)shares	Mar. 12, 2014USD ($)shares
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Share-based compensation, shares outstanding | shares			11,200,000		10,300,000
Restricted Stock Units (RSUs) [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Share-based compensation, shares outstanding, Value			$ 2,000,000
Share-based compensation, shares outstanding | shares			400,000
Share based payment award vesting date			Mar. 16, 2021	Mar. 11, 2020
Restricted stock or unit expense			$ 4,000,000	$ 4,000,000
Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Period of service from grant date stock options awarded not subject to forfeiture			2 years	2 years
Restricted Stock Units (RSUs) [Member] | Executive Officer [Member] | Minimum [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Minimum age of employee with not subject to award forfeiture on condition compliance			55 years	55 years
Restricted Stock Plan [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Shares granted in the period | shares			477,500	466,600
Fair value of grants in period			$ 26,800,000	$ 20,400,000
Unvested Restricted Stock [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Total intrinsic value			90,400,000	62,900,000
Equity awards with an aggregate fair value			$ 21,600,000	$ 14,200,000
Performance Shares [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Shares authorized | shares	86,250	72,900
Performance unit awards approved, Fair value	$ 4,900,000	$ 3,200,000
Provisional awards, terms			Granted units for the 2017 provisional awards will fully vest based on continuous employment through March 16, 2020 and will be settled in shares of our common stock on a one-for-one basis as soon as practicable thereafter.
Performance period, years			1 year
Vesting period, years			2 years
Cash Awards [Member] | Officer and Key Employees [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Provisional awards, terms			The ultimate award value will be equal to the trailing twelve-month stock price on December 31, 2018, multiplied by the number of units subject to the award, but limited to between 0.5 and 1.5 times the original value of the units determined as of the grant date.
Performance period, years			1 year
Vesting period, years			2 years
Provisional compensation cash awards approved for future grant by compensation committee, value	$ 14,300,000	$ 17,400,000					$ 14,600,000	$ 10,800,000
Provisional compensation cash award approved for future grant by compensation committee, units | shares	255,000	397,000	383,000	294,000		220,000	315,000	229,000
Ultimate award value, multiples of original value of the units, minimum | Times			0.5
Ultimate award value, multiples of original value of the units, maximum | Times			1.5
2017 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Cash-based compensation awards, expenses			$ 0
2016 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Cash-based compensation awards, expenses			2,600,000		$ 0
2015 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Cash-based compensation awards, expenses			$ 3,100,000	$ 1,600,000
2014 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Provisional compensation cash award approved for future grant by compensation committee, units | shares			200,000
Cash-based compensation awards, expenses				$ 900,000
Grants vested in period fair value			$ 9,300,000
2013 Provisional Cash Awards [Member]
Common Stock Options Restricted Stock Warrants And Changes In Capitalization [Line Items]
Provisional compensation cash award approved for future grant by compensation committee, units | shares				200,000
Grants vested in period fair value				$ 11,200,000

Investments - Investments Repor

Investments - Investments Reported in Other Current and Non-Current Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Assets	$ 93.3	$ 93.7
Funding Commitments	0.4
Chem-Mod LLC [Member]
Schedule of Equity Method Investments [Line Items]
Assets	4	4
Chem-Mod International LLC [Member]
Schedule of Equity Method Investments [Line Items]
Assets	2	2
Clean-Coal Investments [Member] | Controlling Interest [Member] | Fourteen 2009 Era Clean Coal Plants [Member]
Schedule of Equity Method Investments [Line Items]
Assets	13.3	14.3
Clean-Coal Investments [Member] | Controlling Interest [Member] | Nineteen 2011 Era Clean Coal Plants [Member]
Schedule of Equity Method Investments [Line Items]
Assets	69.5	69
Clean-Coal Investments [Member] | Noncontrolling Interests [Member] | One 2011 Era Clean Coal Plant [Member]
Schedule of Equity Method Investments [Line Items]
Assets	0.7	0.7
Other Investments [Member]
Schedule of Equity Method Investments [Line Items]
Assets	3.8	$ 3.7
Funding Commitments	$ 0.4

Investments - Investments Rep60

Investments - Investments Reported in Other Current and Non-Current Assets (Parenthetical) (Detail) - Clean-Coal Investments [Member]	3 Months Ended	12 Months Ended
	Mar. 31, 2017EntityPlant	Dec. 31, 2016EntityPlant
Fourteen 2009 Era Clean Coal Plants [Member] | Controlling Interest [Member]
Schedule of Equity Method Investments [Line Items]
Number of coal plants | Plant	14	14
Number of variable interest entities | Entity	6	6
One 2011 Era Clean Coal Plant [Member] | Noncontrolling Interests [Member]
Schedule of Equity Method Investments [Line Items]
Number of coal plants | Plant	1	1
Number of variable interest entities | Entity	1	1
Nineteen 2011 Era Clean Coal Plants [Member] | Controlling Interest [Member]
Schedule of Equity Method Investments [Line Items]
Number of coal plants | Plant	19	19
Number of variable interest entities | Entity	17	17

Derivatives and Hedging Activ61

Derivatives and Hedging Activity - Summary of Notional and Fair Values of Derivative Instruments (Detail) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Notional Amount	$ 256,200,000	$ 204,100,000
Derivatives Assets	17,400,000	13,500,000
Derivative Liabilities	12,800,000	17,500,000
Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	250,000,000	200,000,000
Derivatives Assets	12,200,000	11,400,000
Foreign Exchange Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	6,200,000	4,100,000
Derivatives Assets	5,200,000	2,100,000
Derivative Liabilities	$ 12,800,000	$ 17,500,000

Derivatives and Hedging Activ62

Derivatives and Hedging Activity - Summary of Notional and Fair Values of Derivative Instruments (Parenthetical) (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative assets - current	$ 15	$ 12.5
Derivative assets - non current	2.4	1
Derivative liabilities - current	8.9	11.8
Derivative liabilities - non current	3.9	5.7
Foreign Exchange Contracts [Member] | Call Options [Member]
Derivatives, Fair Value [Line Items]
Foreign exchange derivative contracts	95.5	78.3
Foreign Exchange Contracts [Member] | Put Options [Member]
Derivatives, Fair Value [Line Items]
Foreign exchange derivative contracts	95.5	78.3
Foreign Exchange Contracts [Member] | Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Foreign exchange derivative contracts	46.9	61.6
Foreign Exchange Contracts [Member] | Forward Contracts [Member] | Call Options [Member]
Derivatives, Fair Value [Line Items]
Foreign exchange derivative contracts	$ 53.1	$ 57.5

Derivatives and Hedging Activ63

Derivatives and Hedging Activity - Summary of Amounts of Derivative Gains (Losses) Recognized In Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	$ 6.2	$ (2.3)
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion)	(2.4)	(1.2)
Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	0.8	1.1
Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	5.4	(3.4)
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion)	(2.4)	(1.2)
Commission Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	2.4	(3.4)
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion)	(2.8)	(1.2)
Commission Revenue [Member] | Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	2.4	(3.4)
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion)	(2.8)	(1.2)
Compensation Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	1.8
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion)	0.2
Compensation Expense [Member] | Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	1.8
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion)	0.2
Operating Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	1.2
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion)	0.2
Operating Expense [Member] | Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	1.2
Derivative gains (losses) reclassified from accumulated other comprehensive loss into income (effective portion)	0.2
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	0.8	1.1
Interest Expense [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative gains (losses) recognized in accumulated other comprehensive loss	$ 0.8	$ 1.1

Derivatives and Hedging Activ64

Derivatives and Hedging Activity - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) related to hedge ineffectiveness		$ 0.2	$ 0.3
Scenario, Forecast [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Estimated pretax gains to be reclassified from accumulated other comprehensive loss into earnings	$ 4.7

Commitments, Contingencies an65

Commitments, Contingencies and Off-Balance Sheet Arrangements - Contractual Obligations (Detail) $ in Millions	Mar. 31, 2017USD ($)
Note Purchase Agreements [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2017	$ 300
Contractual Obligations, Payments Due by Period, 2018	100
Contractual Obligations, Payments Due by Period, 2019	100
Contractual Obligations, Payments Due by Period, 2020	100
Contractual Obligations, Payments Due by Period, 2021	75
Contractual Obligations, Payments Due by Period, Thereafter	1,775
Contractual Obligations, Payments Due by Period, Total	2,450
Multi Currency Credit Agreement [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2017	395
Contractual Obligations, Payments Due by Period, Total	395
Premium Financing Debt Facility [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2017	104.4
Contractual Obligations, Payments Due by Period, Total	104.4
Interest On Debt [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2017	85.4
Contractual Obligations, Payments Due by Period, 2018	92.9
Contractual Obligations, Payments Due by Period, 2019	88.9
Contractual Obligations, Payments Due by Period, 2020	84.3
Contractual Obligations, Payments Due by Period, 2021	79.4
Contractual Obligations, Payments Due by Period, Thereafter	280.5
Contractual Obligations, Payments Due by Period, Total	711.4
Total Debt Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2017	884.8
Contractual Obligations, Payments Due by Period, 2018	192.9
Contractual Obligations, Payments Due by Period, 2019	188.9
Contractual Obligations, Payments Due by Period, 2020	184.3
Contractual Obligations, Payments Due by Period, 2021	154.4
Contractual Obligations, Payments Due by Period, Thereafter	2,055.5
Contractual Obligations, Payments Due by Period, Total	3,660.8
Operating Lease Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2017	79
Contractual Obligations, Payments Due by Period, 2018	88.7
Contractual Obligations, Payments Due by Period, 2019	73.3
Contractual Obligations, Payments Due by Period, 2020	60.7
Contractual Obligations, Payments Due by Period, 2021	50.3
Contractual Obligations, Payments Due by Period, Thereafter	121.5
Contractual Obligations, Payments Due by Period, Total	473.5
Less Sublease Arrangements [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2017	(0.8)
Contractual Obligations, Payments Due by Period, 2018	(0.4)
Contractual Obligations, Payments Due by Period, 2019	(0.1)
Contractual Obligations, Payments Due by Period, 2020	(0.1)
Contractual Obligations, Payments Due by Period, Total	(1.4)
Outstanding Purchase Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2017	42.3
Contractual Obligations, Payments Due by Period, 2018	32.3
Contractual Obligations, Payments Due by Period, 2019	17.3
Contractual Obligations, Payments Due by Period, 2020	7.3
Contractual Obligations, Payments Due by Period, 2021	2.2
Contractual Obligations, Payments Due by Period, Total	101.4
Total Contractual Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2017	1,005.3
Contractual Obligations, Payments Due by Period, 2018	313.5
Contractual Obligations, Payments Due by Period, 2019	279.4
Contractual Obligations, Payments Due by Period, 2020	252.2
Contractual Obligations, Payments Due by Period, 2021	206.9
Contractual Obligations, Payments Due by Period, Thereafter	2,177
Contractual Obligations, Payments Due by Period, Total	$ 4,234.3

Commitments, Contingencies an66

Commitments, Contingencies and Off-Balance Sheet Arrangements - Additional Information (Detail)	3 Months Ended		183 Months Ended
	Mar. 31, 2017USD ($)ft²EntityEmployeesLetterOfCredit	Mar. 31, 2016Entity	Mar. 31, 2017USD ($)ft²Entity
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Number of square feet | ft²	360,000		360,000
Number of employees will accommodate at new facility | Employees	2,000
Acquired property through lease area, sqft | ft²	306,000
Acquired property through lease percentage of building	60.00%
Operating lease commitment, expiration date	Feb. 28, 2018
Number of companies acquired | Entity	40	32	432
Aggregate amount of maximum earnout obligations related to acquisitions	$ 565,300,000
Aggregate amount of maximum earnout obligations related to acquisitions, recorded in consolidated balance sheet	$ 268,300,000
Tax Increment Financing [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Property tax credit expect to receive period	15 years
Letter of Credit [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Debt	$ 5,000,000		$ 5,000,000
Number of letters of credit issued | LetterOfCredit	1
Letter of Credit [Member] | Security Deposit [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Debt	$ 500,000		500,000
Number of letters of credit issued | LetterOfCredit	1
Letter of Credit [Member] | Self-Insurance Deductibles [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Liabilities recorded on self-insurance	$ 9,300,000		9,300,000
Debt	$ 12,300,000		12,300,000
Number of letters of credit issued | LetterOfCredit	2
Letter of Credit [Member] | Rent-A-Captive Facility [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Debt	$ 6,300,000		$ 6,300,000
Number of letters of credit issued | LetterOfCredit	7
Minimum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Ownership interest	1.00%		1.00%
Minimum [Member] | Tax Increment Financing [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Property tax credit expect to receive	$ 60,000,000		$ 60,000,000
Maximum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Ownership interest	50.00%		50.00%
Maximum [Member] | Tax Increment Financing [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Property tax credit expect to receive	$ 80,000,000		$ 80,000,000
Outstanding Purchase Obligations Related to New Corporate Headquarters Building [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, Total	$ 7,200,000		$ 7,200,000

Commitments, Contingencies an67

Commitments, Contingencies and Off-Balance Sheet Arrangements - Off-Balance Sheet Commitments (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - 2017	$ 0.1
Amount of Commitment Expiration by Period - 2018	0.2
Amount of Commitment Expiration by Period - 2019	0.2
Amount of Commitment Expiration by Period - 2020	0.2
Amount of Commitment Expiration by Period - 2021	0.2
Amount of Commitment Expiration by Period - Thereafter	22.9
Total Amounts Committed	23.8
Letters of Credit [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - Thereafter	21.1
Total Amounts Committed	21.1
Financial Guarantees [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - 2017	0.1
Amount of Commitment Expiration by Period - 2018	0.2
Amount of Commitment Expiration by Period - 2019	0.2
Amount of Commitment Expiration by Period - 2020	0.2
Amount of Commitment Expiration by Period - 2021	0.2
Amount of Commitment Expiration by Period - Thereafter	1.4
Total Amounts Committed	2.3
Funding Commitments [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Amount of Commitment Expiration by Period - Thereafter	0.4
Total Amounts Committed	$ 0.4

Commitments, Contingencies an68

Commitments, Contingencies and Off-Balance Sheet Arrangements - Litigation, Regulatory and Taxation Matters- Additional Information (Detail)	3 Months Ended
	Mar. 31, 2017Companies
Minimum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Number of micro-captive insurance companies organized or managed	100

Commitments, Contingencies an69

Commitments, Contingencies and Off-Balance Sheet Arrangements - Contingent Liabilities - Additional Information (Detail) - Errors and Omissions [Member]	3 Months Ended
	Mar. 31, 2017USD ($)
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Insurance claims, amount retained	$ 5,000,000
Amount of losses in excess of retained amounts	175,000,000
Maximum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Actuarial range value	8,400,000
Minimum [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Actuarial range value	$ 800,000

Commitments, Contingencies an70

Commitments, Contingencies and Off-Balance Sheet Arrangements - Tax - advantaged Investments No Longer Held - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
Income tax credits and adjustments	$ 108.2

Accumulated Other Comprehensi71

Accumulated Other Comprehensive Earnings - Schedule of Accumulated Other Comprehensive Earnings (Loss) Attributable to Controlling Interests (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (763.6)
Ending Balance	(699.1)
Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(47.3)
Net change in period	1.2
Ending Balance	(46.1)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(709.2)
Net change in period	56.8
Ending Balance	(652.4)
Fair Value of Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(7.1)
Net change in period	6.5
Ending Balance	(0.6)
Accumulated Other Comprehensive Earnings (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(763.6)
Net change in period	64.5
Ending Balance	$ (699.1)

Accumulated Other Comprehensi72

Accumulated Other Comprehensive Earnings - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Expense related to pension liability reclassified from accumulated other comprehensive earnings	$ 1,400,000	$ 1,500,000
Income (expense) related to fair value of derivative investments reclassified from accumulated other comprehensive earnings	(2,400,000)	(1,200,000)
Foreign currency translation reclassified from accumulated other comprehensive earnings	$ 0	$ 0

Segment Information - Additiona

Segment Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2017Segment
Segment Reporting [Abstract]
Number of reportable operating segments	3

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information by Segment (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total revenues	$ 1,412.7	$ 1,300.4
Earnings before income taxes	52.3	55.7
Identifiable assets at March 31, 2017 and 2016	11,780.6		$ 11,489.6
Operating Segments [Member] | Brokerage [Member]
Segment Reporting Information [Line Items]
Total revenues	878.5	825.5
Earnings before income taxes	117.7	100
Identifiable assets at March 31, 2017 and 2016	9,422.6	8,681.9
Operating Segments [Member] | Risk Management [Member]
Segment Reporting Information [Line Items]
Total revenues	182.6	179.3
Earnings before income taxes	22.9	24
Identifiable assets at March 31, 2017 and 2016	691.1	690.4
Operating Segments [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Total revenues	351.6	295.6
Earnings before income taxes	(88.3)	(68.3)
Identifiable assets at March 31, 2017 and 2016	$ 1,666.9	$ 1,340.3